Irises forum→Question for the experts: Sun

Views: 477, Replies: 11 » Jump to the end
Name: Lyn Gerry
Watkins Glen, NY (Zone 6a)
Keeps Horses Vegetable Grower Organic Gardener Irises Permaculture Dog Lover
Cat Lover Birds
Image
LynNY
Jun 11, 2021 10:54 AM CST
I have a problem with marginal sun. What I have noticed is some iris do fine in a spot (such as Wintry Sky that has bloomed and increased like crazy each year, while Captain Thunderbolt, planted at the same time literally inches away has never bloomed and barely increased. This has led me to believe that some iris require more sun than others, and I plan to move plants around, to get more sun for those that don't seem to be doing well where they are.

I have been trying to create more sunny areas, but there is only so much in my control because of what surrounds my house.

One question I have is: if the hours of sun are marginal, does it matter if the sun is in morning, afternoon, or split between different times of day?

Hardiness Zones are very far from the whole story about the climate of any given place, so I'm also wondering about cloudy versus clear skies and how that affects iris blooming.

Another question: the thing impacting the sun siutation is very tall trees, many of which aren't even in my yard. Because they are deciduous, the amount of shade increases as the trees leaf out. In terms of encouraging bloom, during what time of year is sun most critical (I'm just assuming that the growth cycle has a time of year when sun matters more than at other times - please correct me if this assumption is wrong).

I have another more obscure question that touches on epigenetics that I wonder if anyone else has noticed/investigated. So every single plant of a given variety is a clone of one original seedling, yet we have all read how one person raves about the excellent performance of an iris, while for another person, that iris is hanging on, barely alive without blooming for years. Aside from the conditions in each person's garden, I am wondering if where the iris was raised matters.

I ask this because, most of my iris come from growers in higher latitudes/four seasons climate. One year, I bought a bunch of iris from a grower in the southern California desert. Those iris all took a long time to bloom, and some of them, even years later have never done well. The original seedlings are from Keppel or Johnson, but the plants my roots came from had been living in the California desert for years.

[Last edited by LynNY - Jun 11, 2021 10:59 AM (+)]
Give a thumbs up | Quote | Post #2527847 (1)
Name: Laurie
southeast Nebraska (Zone 5b)
Irises Butterflies Bee Lover Bulbs Cat Lover Region: Nebraska
Image
lauriemorningglory
Jun 11, 2021 6:41 PM CST
Lots of good questions, Lyn. If I had a choice between morning sun or afternoon sun, I would go with morning sun. After a dewy night, morning sun helps dry the leaves faster than if it remained in the shade for several hours. So this can help with leaf spot. Also, many plants seem to like a bit of shade during the hottest parts of the day--not sure if that is true for bearded iris.
Name: Lucy
Hamilton, MA (Zone 6b)
irises
Charter ATP Member Cottage Gardener Enjoys or suffers cold winters Region: United Kingdom Region: Northeast US Irises
Region: United States of America
Image
irisarian
Jun 11, 2021 7:57 PM CST
I keep one bed for MDB & some SDBs because they bloom before the trees leaf out, putting that bed in shade. At least half day sun is recommended for iris.
Name: Lyn Gerry
Watkins Glen, NY (Zone 6a)
Keeps Horses Vegetable Grower Organic Gardener Irises Permaculture Dog Lover
Cat Lover Birds
Image
LynNY
Jun 12, 2021 3:15 AM CST
So, Lucy, would you say that as long as there is ample sun before bloom, going into shade after bloom doesn't harm the next season's bloom development?

irisarian said:I keep one bed for MDB & some SDBs because they bloom before the trees leaf out, putting that bed in shade. At least half day sun is recommended for iris.


Name: Tom
Southern Wisconsin (Zone 5b)
Irises Vegetable Grower Butterflies Region: Wisconsin Keeps Horses Cat Lover
Dog Lover Keeper of Poultry Daylilies Celebrating Gardening: 2015
Image
tveguy3
Jun 12, 2021 4:05 AM CST
Some irises are just wimpy growers, others would grow anywhere. My Captain Thunderbolt grew poorly in full sun. It finally just disappeared.
Voltaire: "Those who can make you believe absurdities, can make you commit atrocities,"
Name: Lucy
Hamilton, MA (Zone 6b)
irises
Charter ATP Member Cottage Gardener Enjoys or suffers cold winters Region: United Kingdom Region: Northeast US Irises
Region: United States of America
Image
irisarian
Jun 12, 2021 6:58 AM CST
There is early morning sun on the bed; not all shade. But not enough to produce bloom.
Name: aka Annie
WA-rural 8a to (Zone 7b)
Sandsock
Jun 12, 2021 9:36 PM CST
I do think that soil change can have an effect too...I brought some iris (from the 60's) from my mother's lovely soil (like Schriener's) to my scabby sandy soil and they sulked for 2 years even in full sun. Also I bought some from Vegas desert (a climate change and soil change) and they too sulked for 2 years in full sun. Once the iris got used to my soil...they bloom even with shaded roots, but not always...one was behind a shrub that leafed out early and did not bloom this year.
Name: Lyn Gerry
Watkins Glen, NY (Zone 6a)
Keeps Horses Vegetable Grower Organic Gardener Irises Permaculture Dog Lover
Cat Lover Birds
Image
LynNY
Jun 13, 2021 6:13 AM CST
Thank you! This is really helpful info.

Sandsock said:I do think that soil change can have an effect too...I brought some iris (from the 60's) from my mother's lovely soil (like Schriener's) to my scabby sandy soil and they sulked for 2 years even in full sun. Also I bought some from Vegas desert (a climate change and soil change) and they too sulked for 2 years in full sun. Once the iris got used to my soil...they bloom even with shaded roots, but not always...one was behind a shrub that leafed out early and did not bloom this year.


Name: Rosemary
Sacramento, CA (Zone 9b)
Image
reh0622
Sep 17, 2021 1:34 PM CST
I had the same question since I just noticed an iris growing in practically full shade that I had never planted in that spot. When I took a closer look today, I see somehow it was dropped at that spot and over the winter took root in the bare soil. It is on the north side in practically full shade. It might get an hour of sun before sunset, so I also was wondering if it would ever actually bloom in that spot. Probably not?
Name: Robin
Melbourne, Australia (Zone 10b)
Region: Australia Irises Garden Photography Cat Lover Seed Starter
Image
Totally_Amazing
Sep 17, 2021 4:34 PM CST
I asked the same question earlier this year and the answer is yes.
The thread "Will a bud bloom in full shade?" in Irises forum
Name: Rosemary
Sacramento, CA (Zone 9b)
Image
reh0622
Sep 18, 2021 12:35 PM CST
Thank you for posting that link, Robin! It's so helpful reading of other's experiences! Thank You!
Name: Ian McBeth
Lincoln, NE (Zone 5b)
Try Naturalizing perennials! :)
Amaryllis Hostas Garden Photography Butterflies Bulbs Bee Lover
Enjoys or suffers hot summers Foliage Fan Lilies Daylilies Irises Region: Nebraska
Image
SonoveShakespeare
Oct 1, 2021 9:42 AM CST
Be aware that the leaves and stalks tend to droop if grown in shade. So stakes may be needed to prop up the blooms.
Not only people give others signs, but plants do too.

« Garden.org Homepage
« Back to the top
« Forums List
« Irises forum
Only the members of the Members group may reply to this thread.

Member Login:

[ Join now ]

Today's site banner is by ge1836 and is called "SEMPS #2"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.