Expert: Long Island Gardener - 6/25/2007

Question
I planted about 10 gladiolus last year or the year before and this is the first year I have seen blooms on them-I have four or five that are 5ft.tall and had to stake them & they are beautiful.  I have 2 more about 3ft.tall that haven't bloomed yet but are getting ready to.  Then there are about 3 or 4 more that are just stalks about 2 1/2 to 3 ft that don't have any signs of blooming. I don't know anything about them.  How long do the blooms last and how long can I expect them to bloom?  All summer?  Until frost? or will they just bloom this one time and will be over for the season, if so, how long will these blooms stay on?  Thanks

Answer
A healthy Gladiolus stalk grows from 2 to 6 feet tall, with two dozen or more flowers on a single stem.  They're beautiful in the garden, beautiful in the vase, and beautiful just to look at.  And they're so easy.  So what went wrong with yours?

A Gladiolus must be at least 3 years old to bloom.  Are yours not mature yet?  Were they purchased at a bargain, for a song?

These also need bright sun -- lots of it -- to bloom well.  How much sun are yours getting?

Sandy rich loam is the best kind of soil for Glads.  If it's too heavy, they'll underperform.  Compost, manure or peatmoss will fix that.  These flowers like a low pH between 6 and 6.5 and LOTS of sun -- sheltered from wind to avoid tipping or breaking and staked.  Corms should be planted in Spring, generally 4 to 6 in deep.  If your Summers are VERY hot, plant these in Winter to get blooms prior to Summer heat waves.  Staking is always important.  They take 60 to 100 days to bloom.  Always leave two to four leaves behind after you cut the flowers for corms mature.  Once in the water, they'll open from the bottom up; how long they last depends on the temperatures and the water, but my average is about a week to 10 days of peak performance.

Thrips are a major problem for Glads.  They burrow into buds while still inside the sheaths, causing deformed flowers when they open.  Thrips are able to survive winters by spending them on the corms.  See any symptoms?

If you are in Zone 7 or South, you can keep these in the ground with a little mulch over the top during the winter, and they'll come back next year.

Thanks for writing.  Any questions, I'm here!