Expert: Long Island Gardener - 9/1/2007

Question
This is the first season I have grown Glads, and I planted in 2 seperate locations. One did very well and in the other more sunny location  all the new blossoms whithered  before they could open... now all the stalks are finished and I need to pull them up. I live in the fingerlakes region of NY State and wondered  How long should I wait to pull them? Do the stalks need to be brown and dry? and also..... how do I store them for the winter... I have heard I should wrap them in newspaper? I want to grow them every year... they are absolutely beautiful.

Answer
The Associated Press posted an article on winter care of summer bulbs.  You can access it here:

http://www.lubbockonline.com/news/101197/LC0262.htm

'As you dig Gladiolas, notice the shriveled, old bulb that you planted, still attached to one or more fresh, new bulbs that have grown atop it.  Botanically, these are corms, swollen stem tissue at the base of the plant.  Small corms, which need a couple of seasons' growth before they attain flowering size, cling loosely to the now-shriveled mother corm...Separate and save new corms and toss out the dead corm.'

It is just important, though, to remove the spent flower stems.  Cut the stems JUST UNDER the bottom flowerbuds.  Doing that will guide energy toward the Corm -- instead of spending it on seed production.

Have you considered the possibility that you may not need to lift your Gladiolas every year?

If the ground in your region does not freeze in Winter, digging these up is unnecessary.  Your Glads will also do better stored dry, out of the ground, if your Soil tends to be icy and wet through Winter.  At the very least, the next year's blooms will be more vigorous if you dig them up and store properly -- and newspaper sounds like a very good idea.  You can also use dry peatmoss, in a box.  Plastic would be asking for trouble; it prevents flow of air, and is not a good way to store any bulb or plant.

Now, let's go over the blossoms that withered and did not open.

Bonide, the chemicals manufacturer, posts a Gladiola Problems page on its website:

http://www.bonide.com/solutions/flowers/gladiola.htm

Under 'Buds brown, die' they say: Thrips.

Thrips are a Gladiola Nightmare.  Sometimes it's just silvery or brown spots on the leaves or flowers, sometimes dark droppings speckling the foliage.  Or they can blast an entire season's worth of flowers.

Thrips are little -- less than 1/20th of an inch long.  They devour leaf and flower tissue, sucking the plant juice, laying eggs along the way.  Sometimes the Glads are tough enough not to notice.  Others are not so lucky.

What to do?

First, you have to understand I am dead set against chemicals.  They screw up a lot of things, including the humans who apply them, and there are a lot of alternatives these days.  We simply know a lot more than we used to about plants and bugs and Fungi.  So why not put Science to use instead of using outdated methods and products?  And often, the Science is cheaper.

So getting back to your Thrips, there are several ways to get rid of them.  You may like some and not others.

One relatively recent finding was that reflective mulches tend to really confuse these insects.  And when they get confused, they cannot figure out where the flowers and the leaves are.  They generally would rather just leave.  I get a big kick out of this solution, but considering you are dealing with an ornamental garden and not a field of vegetables, repelling Thrips would have to be a lot less ugly to be of any serious use.

IPMLabs of Locke, NY, promotes the predatory mite Neoseiulus cucumeris, Orius insidiosus (known as the 'Minute Pirate Bug'), and H. miles as first rate (if expensive) Thrips-targeting IPM solutions.

The Dow AgroSciences product 'Conserve' uses Dow's brand of the Thrips-tackling Fungus Saccharopolyspora spinosa, which they package as 'Spinosad'.  Farmers and commercial growers are the target market, so you won't see it profiled in Woman's Day or Forbes.  But a Thrip is a Thrip, whether it's chewing your Gladiola Buds, devouring your Tobacco Leaves or ripping up the petals of your English Roses.

The Green Methods website has some lovely closeup photos of these very annoying pests:

http://www.greenmethods.com/incl_pages/bb_thrips.php

'Two of their stages, the prepupal and pupal stages, at least for some species, are spent in the soil ... With the right tools they can easily be controlled down-under.  Right tools like the predatory mite Hypoaspis miles.'  Buglogical Controls sells H. miles:

http://www.buglogical.com/hypoaspis_control_fungusGnats/hypoaspis.asp

Buglogical points out that H. miles is 'most effective when applied to soil before Fungus Gnat populations are established.'  But it is not a practical solution in your region -- Winters are way too cold and you would have to restock the supply each year because H. miles would not be able to survive.

So we go to Plan B.  Hot Pink Sticky Traps.  Because as the National Sustainable Agriculture Information Service points out, 'Hot-pink sticky cards have been found to be the most attractive color for trapping thrips.'  You can read their entire Thrips control page here:

http://attra.ncat.org/attra-pub/gh-thrips.html

You can make your own Sticky Traps.

You'll need some SHOCKING PINK CARDBOARD or Index Cards, a few Paper Clips, a pair of Scissors and a product called 'TANGLEFOOT', used to repel Pigeons from rooftops and outside windows.

Cut out an index-card-sized piece of the Shocking Pink Cardboard.  [Note: This MUST be Shocking Pink or Yellow!  White, Black, Blue, Orang, Green are NOT YELLOW or SHOCKING PINK.]

Spread the Tanglefoot on the Cardboard/Index Card.  In the middle, punch a little hole and thread it with a Clip, then hang it off a branch.

It should be hanging near the soil.

That's where newly hatched Fungus Gnats pop and jump all over the place.  They will be stuck to your trap in no time.

You can't stop them from coming back, but you can catch so many that the problem is over for the season.

Besides the Sticky Traps, when you plant your Glads next year, make sure to plant a border of Garlic.  Notes NCAT, 'A large greenhouse grower in The Netherlands found that Garlic plants are an effective way to repel Thrips.  He uses three potted Garlic plants for every 30 sq ft of bench area.'

Some good old fashioned Insecticidal Soap will also work, but there is still a lot of collateral damage with that -- Ladybugs, etc., so it is not on my short list of preferred treatments.  But it's safe and unlike some of the other things out there it won't kill anyone.

I agree, Glads are gorgeous.  Keep yours in a heated Garage or a cool basement -- someplace dark, and not so cold that water will be cool enough to drink and still be called Refreshing.  It should melt ice cream.

I think I've covered everything here.  Let me know if I've m issed something, and if you have any other questions I'm glad to address those too.  Thanks for writing.