Expert: Long Island Gardener - 9/14/2007

Question
When do I dig my gladious and dahlias bulbs in the fall

Answer
For Dahlias, wait for the first light frost to set down in your Zone 5, and cut all remaining flower stalks down to just 3 inches above the ground.

Keep the Dahlias in the ground another 10 days or so.  Then use a pitchfork to gently loosen and then dig up the whole clump.  This task really is done best with a pitchfork.  You cannot be too careful about this, Neita.  You don't want to damage the tuber.  Be careful.  Be gentle.

Lots of novice gardeners try to short-cut this exercise.  They'll go out there and yank the Dahlias out of the ground.

Don't make that mistake -- you destroy the tuber and transform the whole plant into just another a compost pile candidate.

Instead, prod and lift the tuber carefully, then use a garden hose to clean the clump.  Cut the roots off with a scissors and let the clump dry.

You can store your tuber or try your hand at propagation.  This is the best thing going because you multiply plants you already have showned you can grow.

Slice the tuber with sharp scissors or a knife.  Carefully divide clumps in half by splitting with pruning shears.  You'll find a handy illustration of this procedure at the swan Island Dahlias website:

http://www.dahlias.com/index.asp?PageAction=Custom&ID=2#13

Every tuber needs an eye at the point where the crown slightly enlarges.

You'll notice the eyes are located mainly near your Dahlia stem.  Prepare a homemade disinfectant by mixing a cup of Bleach to 3 gallons of water and let your tubers soak there for 15 minutes to 1/2 hour, then dry on newspapers.  Keep them out of the sun.

Some people overwinter their tubers in plastic bags with vermiculite.  Me, I prefer to keep them in peat moss in the basement, in an open plastic container, and mist them every few weeks with some water.

Now let's discuss your Gladioluses.

These technically are lifted a little later.  Using the same pitchfork, dig your Gladiolus bulbs up when the leaves turn Brown -- and make sure to do this before a real hard freeze renders the garden surface hard as a rock. Make your cut right above the bulbs.  Toss out any diseased corms.

Let them rest a month on a shelf in the basement or the garage (which should be frost free).  Then wash them off well, and clip off the dried up roots (leave husks on).  You can find some good drawings of this at Illinois Coooperative Extension:

www.urbanext.uiuc.edu/bulbs/bulbbasics.html

This is a very TRICKY autumn responsibility, Neita.  For me, this would not be the first year I did not dig my Dahlias and Gladiolus up due to waiting too long.  Last year, our first hard freeze seemed to come out of nowhere and the ground was solid rock after that.  To my amazement,
half my Dahlias and Glads survived anyway -- thanks to good luck and excellent drainage.

Keep the collection dark and frost free, storing it someplace cool where temps never exceed 55 degrees F.  And wait for Spring.