GARDNERS will wake up any day now with the astonishing insight that it's too late to order the things they've been thinking about all winter. Indeed, this may be the place to announce that as far as I'm concerned, it is now spring, and we are entitled to stomp around if there is ice or snow.

Every spring it is distressing to find gardners thick as thieves at large garden centers buying Norway maples at bargain prices. They have a new place, possibly, and of course want a tree or two. They are assured, by any number of loons, that a Norway maple is nice, and they find it doesn't cost much on sale so there they go.

No. A Norway maple is not what they want. They want a Washington thorn. This is an elegant small tree usually not more than 15 or 20 feet high, with a nice rounded top. Until recently, when a set of Huns working on the sidewalk or gas main or something tore up the edge of M Street by the side of the National Geographic Society -- severly damaging that admirable row of Washington thorns -- I could have recommended you to drop by to see them. They are nice examples of slothful would be a good novelty for dealing with work crews that needlessly damage Washington thorns, dogwoods and so on.

Because the thorn is a flawless tree, flowering in mid-May with modest pretty clusters of medium bright red berries, this thorn is rarely offered for sale. Kelly Bros. Nurseries, Dansville, N.Y. 14437, is one source of plants.

If a larger tree, but still small if compared to forest trees, is wanted then the mountain ash, Virginia fringe, sassafras, persimmon, dogwood, holly, the Asian magnolias such as MM. kopbus, salicifolia, stellata (which grows extremely well in Washington and usually stops at about 15 feet), denudata, the hybrid group called soulangeana, are all fine. Many crabapples, some flowering cherries, flowering peaches, flowering plums are all good.

Some viburnums (V. seiboldii, for one) can reach the dignity of a small tree. The flowering ash, the elegant chaste tree, Vitex macrophylla, which flowers in either blue or white and rarely grows above the second-floor windows of a house, are handsome.

Golden rain trees (Koelreuteria paniculata ) will reach 25 or 30 feet, and the quite elegant Laburnum vossi with masses of flowers like yellow wisteria in April or early May, stops at 20 feet.

The shadblows, Amelanchier, vary in size, from shrubs to trees 40 feet high, but all agree in flowers as fragile and delicate as a dream, little wisps of white. Everyone admires these in the woods, where they bloom well before the dogwoods, but they are equally delightful in the garden, however fleeting their flowers may be.

The crape myrtle is rarely thought of, but when given a good sunny sheltered spot, a bit of attention to watering in dry summers, and a mulch of manure every other winter, it soon makes a shrub of 20 or 25 feet tall with beautiful flowers, foliage, bark, trunk. How often this is the sort of plant you really want in front of a row house or on a small city lot.

The black locust is largely sneered at because it is brittle and sheds spare branches in storms and gets borers and is forever dropping flowers or leaves or something. For all that, it is unsurpassed by any other tree in the world for beauty, and I only wish I had one in place of the hugh red maple in front of my house. (The red maple is a superb tree and I could never bring myself to cut down a fine old one, but it grows very large and moreover makes life pretty dusty for anyazaleas you may be growing beneath it.)

If there is room for a really large tree, the rather neglected willow oak is a fine choice. Both the bald cypress and the dawn redwood (Taxodium and Metesequoia ) are glorious trees, feathery in effect but with trunks as good as beech or oak, and a splendid change from the Norway maple beneath which nothing will grow.

Quite apart from small trees, an endless assortment of other things should be planted in March. By all means get the asparagus and rhubarb ordered (or bought locally) in time for early March planting. A few freezes after you plant them will do no harm whatever.

All fruit trees should go in in March, and let me urge town gardners to stick to peaches or else dwarf fruit trees grafted on stock that reduces their normal height or spread. How often the young gardner is carried away with a cherry or plum, and at last cannot believe how huge a fullsized plum grows. Apart from saving space by growing dwarfed fruit trees (and many of them will reach half the bulk of a full-sized fruit tree, so they aren't all that dwarf) it is far easier to spray a small tree than a large one. a

Peonies should be planted in October and irises in July or August, but March is fine for roses. Oriental poppies in pots (otherwise August and September is the right time for them) and virtually all perennials. Let me put in a word for the Russian sage, Perovskia, and the lad's love, Artemisia abrotanum, among perennials that are not especially showy, but which do much to give the garden the look you want it to have without quite knowing why. m

When ice thaws on lily ponds, it is well to rake the bottom to catch any wretched Normay maple leaves that have fallen in since November when (of course) you cleaned it nicely. maples and hemlocks that have given you pain for years.