Photo by Melody

PlantFiles: Tall Morning Glory
Ipomoea purpurea 'Kniola's Black'

Family: Convolvulaceae (kon-volv-yoo-LAY-see-ee) (Info)
Genus: Ipomoea (ip-oh-MEE-a) (Info)
Species: purpurea (pur-PUR-ee-uh) (Info)
Cultivar: Kniola's Black

Synonym:Convolvulus purpureus
Synonym:Ipomoea hirsutula
Synonym:Ipomoea purpurea var. diversifolia
Synonym:Pharbitis purpurea

2 vendors have this plant for sale.

18 members have or want this plant for trade.

Vines and Climbers

12-15 ft. (3.6-4.7 m)
15-20 ft. (4.7-6 m)
20-30 ft. (6-9 m)

15-18 in. (38-45 cm)

Not Applicable

Sun Exposure:
Sun to Partial Shade
Light Shade

Parts of plant are poisonous if ingested

Bloom Color:
Dark Purple/Black

Bloom Time:
Mid Summer
Late Summer/Early Fall


Other details:
May be a noxious weed or invasive
This plant is attractive to bees, butterflies and/or birds
Average Water Needs; Water regularly; do not overwater
Self-sows freely; deadhead if you do not want volunteer seedlings next season

Soil pH requirements:
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
7.6 to 7.8 (mildly alkaline)

Patent Information:
Unknown - Tell us

Propagation Methods:
From seed; stratify if sowing indoors
From seed; sow indoors before last frost
From seed; direct sow after last frost
From seed; germinate in a damp paper towel
Scarify seed before sowing

Seed Collecting:
Allow pods to dry on plant; break open to collect seeds
Properly cleaned, seed can be successfully stored

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By michael10
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By oldcogers
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By poppysue
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By poppysue
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By arsenic
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By rebecca101
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There are a total of 12 photos.
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3 positives
2 neutrals
2 negatives

Gardeners' Notes:

Neutral Prunerman On Jul 6, 2012, Prunerman from Middleton, MA wrote:

Just bought and planted this Kniola in my garden against bunny ears plants for a contrasting light colored background. It will (hopefully) climb up a freestanding wrought iron trellis.
In a month or so, I'll post a progress note.

Negative Q734 On Jul 10, 2010, Q734 from Allen Park, MI wrote:

A couple of years ago I ran across Kniola blacks online and ordered some.

As they went to seed I saved them carefully as the flowers are a beautiful deep dark velvety purple, and yes, almost black, but fabulously so. They're a deeper darker purple than a Grandpa Ott and without the pink throat.

Fast forward a couple years and I'm yanking them out as they would aggressively compete with and will hybridize HBs, thoroughly dominating HBs, plus they're a smaller bloom than a good heavenly.

So now when I see a determined Kniola, which have a fuzzy stem as opposed to the smooth one on a Heavenly, I yank, yank, yank.

They are a sure thing tho, and very strong. Funny I never would have imagined me pulling these out! But if I wanted the heavenlys that my dh & I love so much, they must go:/

2012 update(4 years after planting these):
I'm changing my neutral rating to a negative because these are REALLY HARD TO GET RID OF.
The seeds must last a really long time in the soil !!!
They're in our lawn trying to sprout even.
Preen has helped some in the front yard but I don't spread preen where the dogs are in the back yard.

Be very sure you don't want another type of morning glory before you plant these, or at the very least keep them sequestered.
They will act all pitiful at first- making you feel oh so sorry for them- then BOOM!!!! Bubba moved in and won't leave!

Positive dixielol On Nov 13, 2009, dixielol from Dunmor, KY (Zone 6a) wrote:

I've had a hard time getting this plant to "climb" on its own & resorted to tieing it up with string. In my opinion, the flowers are well worth the trouble of tieing it up. Had a lot of compliments on it. It also gave me alot of seeds!

Positive gardenbugde On Aug 31, 2008, gardenbugde from Smyrna, DE (Zone 7a) wrote:

This is my first year for Kniola's Black Knight. It was started indoors in peat cups and transplanted in May. It has grown well, although the vines are not as thick as other cultivars. The color is lovely though and will probably use them as part of a "mix" next year. Seeds mature quickly too.

Neutral rebecca101 On Mar 14, 2008, rebecca101 from Madison, WI (Zone 5a) wrote:

This morning glory starts blooming earlier than others, while it is still vining (early July for me). The flowers are a very dark purple color. Flowers were mostly hidden by the leaves. They did not flower very profusely, and in general did not make a very good garden display. The vine is very vigorous and gets huge and heavy - it toppled the trellis it was on by mid-summer (8 ft. tall teepee made of four very thick posts sunk deep into the ground!). I direct seeded into the garden in May, and the seeds did not germinate that year but the next year instead - they may need vernalization or winter sowing.

Negative Marshmellow On Jul 29, 2004, Marshmellow from Fitchburg, MA wrote:

Alright, I'd like to know who came up with this color scheme to a wonderful vine, they should be fired.

I got a package of "Random vines" and this is the dominant type that's growing. I can see why it's the dominant type after seeing it bloom. They must get a deal of the seeds of the types that don't sell and put them in the random vine package, after seeing this variety I can see why it doesn't sell. Listen people, it's dark, very dark, so dark that in the shade it blends in and you don't notice the flower... and in the sun it's so dark it absorbs the light and you can't notice the flower. Either way, you don't notice the flower! The pictures tell it all, it's not a stop people walking by to see the flowers because no one's going to notice them. It's to the point I have to get within 10 feet of the vine to see any of the flowers, they blend in near perfect with my dark brown house. I wanted people walking by to notice it. I have trouble noticing the flowers when I'm weeding in front of it and have to follow the vines to see if any flowers are blooming because they camouflage brilliantly with their surroundings.

The good point is, it appears to grow faster and stronger than other types of morning glories. In a matter of 4 months the main vine has climbed to the top of my house, back down, and up again. I've never seen a longer/taller morning glory. Maybe that's why it's called the "Tall Morning Glory", also 'Kniola's Black' because the flower is almost black. Also, it appears hardier than other morning glories. But, what good is it since you can't see the flowers.

I hate it, don't get it unless you have some fetish for dark, dark, purple flower that borders on being black. I can only see any practicality for this flower against a white background. I will never buy those random seed packages now that I know this is what's mostly in them. I have so many of these growing and I get so disappointed when I see yet another one of my vines bloom for the first time from that package and it's yet again one of these. Very disappointing.

Positive michael10 On Jun 26, 2003, michael10 wrote:

Very beutiful flower! In my opinion the correct name should be: Knowlian´s black


This plant has been said to grow in the following regions:

Tuskegee, Alabama
Carmichael, California
El Sobrante, California
Elk Grove, California
Richmond, California
Centerbrook, Connecticut
Smyrna, Delaware
Zephyrhills, Florida
Dunmor, Kentucky
Fitchburg, Massachusetts
Allen Park, Michigan
Bay City, Michigan
Lafayette, Tennessee
Thompsons Station, Tennessee
Brazoria, Texas
Jacksonville, Texas
Plano, Texas
Spring Branch, Texas
Vancouver, Washington
Madison, Wisconsin

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