Germination Guide

Click on a species name below to see it's germination tips.
Search for a genus or species by entering specific words or parts of words.
Click Reset anytime to start a new search.

Iris douglasiana hybrid

F

Sow @ 4°C.

*

This species needs special care as described.
soak and rinse in clean water daily x 4 weeks, resent disturbance, pot up individually and plant out ASAP
Iris douglasiana x innominata

F

Sow @ 4°C.

*

This species needs special care as described.
soak and rinse in clean water daily x 4 weeks, resent disturbance, pot up individually and plant out ASAP
Iris ensata

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed 1 week in toilet tank then chill 3 months or place outdoors over winter before germinating at warm temperature; bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris ensata 'Eden's Paintbrush'

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed 1 week in toilet tank then chill 3 months or place outdoors over winter before germinating at warm temperature; bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris ensata 'Geisha Girl'

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed 1 week in toilet tank then chill 3 months or place outdoors over winter before germinating at warm temperature; bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris ensata 'Henry's White'

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed 1 week in toilet tank then chill 3 months or place outdoors over winter before germinating at warm temperature; bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris ensata 'Lapetus'

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed 1 week in toilet tank then chill 3 months or place outdoors over winter before germinating at warm temperature; bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris ensata 'Rose Queen'

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed 1 week in toilet tank then chill 3 months or place outdoors over winter before germinating at warm temperature; bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris foetidissima

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris fulva

!

Sow immediately. The viability of these seeds is short or the species propagates best with fresh seed. Stored seed might be coaxed into germination with temperature cycling and patience.

*

This species needs special care as described.

C

Sow @ 20°C for 3 months, then place @ 4°C for 3 months.
sow fresh
Iris germanica

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed, prechill 4weeks,(or L) bring indoors once germinated to avoid temperature shock, transplant at 4 leaves
Iris gracilipes

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris graminea

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris graminifolia

*

This species needs special care as described.

3

Requires light or the small seeds should be surface sown. See https://www.youtube.com/watch?v=RgkXUSI1GWo&index=1&list=UUJfYCNSWCIuOB2...

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

A

Sow @ 20°C. Seed germinates within 3 months.
soak and rinse in clean water daily x 4 weeks
Iris halophila

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.
ow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris histrioides x winogradowii

*

This species needs special care as described.

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris hookeri

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris humilis

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris hybrid

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris iberica

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
very difficult, few seeds germinate, sow fresh or soak stored seed, bring indoors once germinated to avoid temperature shock, transplant at 4 leaves, may not germinate for 3 years or more
Iris illyrica

*

This species needs special care as described.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris innominata

C

Sow @ 20°C for 3 months, then place @ 4°C for 3 months.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
soak and rinse in clean water daily x 4 weeks, resent disturbance, pot up individually and plant out ASAP
Iris japonica

G

Sow @ 4°C for 3 months, then place @ 20°C for 3 months.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris kaempferi

H

Use repeated cycles of 4°C, then 20°C for 3 months each. Germination is very prolonged.
Iris kamaonensis

D

Use repeated cycles of 20°C, then 4°C for 3 months each. Germination is very prolonged.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris lactea

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris laevigata

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris laevigata 'Variegata'

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris latifolia

C

Sow @ 20°C for 3 months, then place @ 4°C for 3 months.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris louisianica 'Dorothea K. Williamson'

*

This species needs special care as described.

A

Sow @ 20°C. Seed germinates within 3 months.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris lutescens

A

Sow @ 20°C. Seed germinates within 3 months.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris maackii

*

This species needs special care as described.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris magnifica

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
very difficult, few seeds germinate, sow fresh or soak stored seed, bring indoors once germinated to avoid temperature shock, transplant at 4 leaves, may not germinate for 3 years or more
Iris magnifica 'Agalik'

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

G

Sow @ 4°C for 3 months, then place @ 20°C for 3 months.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris magnifica 'Alba'

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

very difficult, few seeds germinate, sow fresh or soak stored seed, bring indoors once germinated to avoid temperature shock, transplant at 4 leaves, may not germinate for 3 years or more
Iris masiae

A

Sow @ 20°C. Seed germinates within 3 months.

*

This species needs special care as described.
takes 4 months to germinate; grow cool indoors 1st winter
Iris milesii

G

Sow @ 4°C for 3 months, then place @ 20°C for 3 months.

2

Requires darkness.

*

This species needs special care as described.
sow fresh or soak old seed, bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris missouriensis

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed, leave full 6 months at 4°C to get 90% germination or 4 months to get 60% germination; bring indoors once germinated to avoid temperature shock, transplant at 4 leaves
Iris ochroleuca

G

Sow @ 4°C for 3 months, then place @ 20°C for 3 months.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
Iris orchioides

*

This species needs special care as described.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

may take up to 3 years to germinate
Iris orientalis

C

Sow @ 20°C for 3 months, then place @ 4°C for 3 months.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris Pacific Coast Hybrids

G

Sow @ 4°C for 3 months, then place @ 20°C for 3 months.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris pallida ssp. illyrica

*

This species needs special care as described.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris planifolia

!

Sow immediately. The viability of these seeds is short or the species propagates best with fresh seed. Stored seed might be coaxed into germination with temperature cycling and patience.

*

This species needs special care as described.

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris prismatica 'Alba'

*

This species needs special care as described.

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris pseudacorus

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.

3

Requires light or the small seeds should be surface sown. See https://www.youtube.com/watch?v=RgkXUSI1GWo&index=1&list=UUJfYCNSWCIuOB2...

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris pseudacorus 'Variegata'

*

This species needs special care as described.

3

Requires light or the small seeds should be surface sown. See https://www.youtube.com/watch?v=RgkXUSI1GWo&index=1&list=UUJfYCNSWCIuOB2...

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris pumila

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves; Gabriela Costea reports it may germinate as A x 2 weeks if seed is fresh and moist
Iris reichenbachii

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris reticulata

*

This species needs special care as described.

D

Use repeated cycles of 20°C, then 4°C for 3 months each. Germination is very prolonged.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris rosenbachiana 'Varzob'

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

G

Sow @ 4°C for 3 months, then place @ 20°C for 3 months.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris ruthenica

*

This species needs special care as described.

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed
Iris sanguinea

E

Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.

6

Requires scarification. Nick or rub between sheets of sandpaper.  See https://youtu.be/icB9HrqdQqU  Seed coat of Baptisia and Oxytropis and other Fabaceae can be scarified by soaking in boiling water. See http://botanicallyinclined.org/continuing-the-sowing-in-hot-water

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
nick carefully; sow fresh or soak old seed; prechill 4 weeks, (or L), bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris setosa

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris setosa alba

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris setosa v. arctica

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris setosa v. canadensis

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris setosa v. nana

*

This species needs special care as described.

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

L

Give sown seeds several weeks @ 20°C to imbibe water (perhaps even germinate!), then expose to fluctuating outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in spring. See https://www.youtube.com/watch?v=SO_KKbGYTEM

sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris sibirica

A

Sow @ 20°C. Seed germinates within 3 months.

3

Requires light or the small seeds should be surface sown. See https://www.youtube.com/watch?v=RgkXUSI1GWo&index=1&list=UUJfYCNSWCIuOB2...

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

*

This species needs special care as described.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves
Iris sibirica 'Alba'

*

This species needs special care as described.

3

Requires light or the small seeds should be surface sown. See https://www.youtube.com/watch?v=RgkXUSI1GWo&index=1&list=UUJfYCNSWCIuOB2...

7

Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard floaters and the water used for soaking. See https://youtu.be/dhL57pqnHHQ

A

Sow @ 20°C. Seed germinates within 3 months.
sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves