I planted a batch of gladioluses last week, even though we may have a snow in April -- it will do them no harm.
Mine go four inches deep, since the corms are on the small side and my soil is heavy. Large corms in lighter loams might be planted six inches deep. The soil is firmed down with light pressure of the foot, and if the ground seems on the dry side a light watering is good.
It depends on the weather and the depth of planting how long it will take the leaves to appear. Three or four weeks, usually. I have not found it necessary to water the gladioluses once they are planted, but use common sense here; if the spring should be quite dry (which rarely happens) then a good soaking once a week is indicated.
They need no special care, and if grown in a reasonably sheltered spot they need no staking. But, again, use common sense. If you plant top-size corms of giant varieties that grow to five feet or more, clearly each one will have to be staked.
My smaller corms will produce flowers used just for cutting, not garden decoration, and will be cut as the first floret opens. If they are grown for garden decoration, in clumps, then it makes sense to support the tall stems one way or another. One year I used highway mesh (commonly sold to support tomatoes in cylindrical cages) painted black. It was formed into a cylinder 2 or 3 feet in diameter and about 4 feet high, and as the clumps of gladioluses grew, the mesh was hardly visible, but gave strong support in summer storms. A spike with a number of florets open is more easily blown down by wind than one cut just as the first floret shows color or opens.
If you grow these flowers for cutting, they do perfectly well in a row in a spare sunny place -- much as you might grow a row of onions or bush beans. I plant my small corms five inches apart in the row. As the plants begin to show their bloom stalks in the sheaves, a sprinkling of 5-10-5 fertilizer may be used along the row, scratched in and watered.
If you plant mixed varieties they will bloom over a period of several weeks, not all at once. If you want them to bloom at the same time, then plant clumps of just one variety. And keep this in mind if you grow them for cutting. You may wind up planting more than you first planned, when you realize their blooming period will occupy some weeks. Plantings can be made every two or three weeks into June, or you can plant them all now and let them start blooming in July and finish whenever they finish.
Sometimes those who have planted them on the deep side in good loam will leave the corms undisturbed. I have seen good flowers from clumps that have been left alone five years or more.
These clumps get congested, the flower spikes smaller, yet the garden effect can be ornamental enough. But it is rather slight trouble to dig the corms up in October, whack off the leaves and store them dry indoors.
In early March they are sorted over and any bad-looking ones discarded. Many gardeners like to shuck off the papery covering before planting, and treat the corms (with a dust or liquid solution) against thrips and suchlike vile creatures before planting. Often this is not necessary.
It goes without saying, probably, that if your dogs, children or other dangerous animals romp through the gladioluses, the flowers will not thrive. This is not a shortcoming of the flower. In small city gardens one often has to compromise. This past week the terrier has snapped off several young peony shoots. You know how brittle they are as they first emerge. And the hound has lain, as usual, on those daffodils that grow in the sunniest and most sheltered part of the garden. You will notice it does not bother dogs at all if the plants happen to be in full flower.
I knew a man who raised dachshunds and irises both. He bordered every single iris bed with those low iron pickets, painted white, and the effect was more blinding than necessary, I thought, but effective. It would not be effective at all against terriers or most other dogs, but served well against bassets as well as dachshunds.
With gladioluses and dogs, it is best to run the pickets or other low fencing right against the row of plants, leaving gaps here and there for the mutts to jump through. Otherwise, they will plow through.
These low pickets or wire barriers are not effective when used to protect a bed 2 by 4 feet, say. You'd think they would be. I had one such tiny patch of pansies planted in the fall and they were superb until a few weeks ago. They were not hurt by the winter -- partly because I used small plants in October, which bear the winter better than large ones -- and I was mentally gathering pansies in late March, every time I saw them. Unfortunately, something attracted the terrier and he took to bounding into the center of this small patch, not much bigger than he is, and simply ground the plants away. In other places, where the pansies are in small rows, they are fine, since the metal pickets are right against the row. The dog leaps over and clears the plants.
If the gardener should notice (and he will if he is not fully blind) holes about 20 inches deep and 7 inches wide, he may resolve not to have terriers again, but in the meantime, to save young roses or clematis, he may set bricks about the plants, without mortar, of course, flat on the ground. This not only discourages digging but precludes it.
If you have ever wondered why Welsh terriers have tails a certain length, it is to grab them by, to pull them out of holes. Recently I have pulled Max out of several, and find satisfaction in having arranged his tail the classic length. He comes right out. Sometimes some terriers will dig some feet underground, which is highly dangerous. These things must be thought of and precautions taken, not only for the dog's sake but for the garden's.