CONCRETE AND artificial grass are not the answer, but abolishing the usual roses and irises may be.

The saving of time and labor in the garden is not important if you have an endless supply of both, but many gardeners find themselves unable to keep it all together, as you might say.

There is no magic answer, but there are some answers all the same, if the gardener wishes to ask the right questions.

First off all, a large garden requires more sweat than a small one. In the great garden of Versailles, to give an example, there is nothing of much interest that I could detect apart from the terraces, avenues of trees and fountain basins. But if trees are in rows a mile long, then the mree removal of dead branches becomes quite a chore, and even if one has rather low standards for a lawn, merely keeping the brambles out is a formidable undertaking if the lawn runs for thousands of feet.

I say nothing of the repair of stonework, beyond noting that pedestals crack, urns topple, pools leak sooner or later, pumping systems fail and have to be rebuilt. As one of our wits once observed, there is nothing so strong but time decays.

Even if there are no plants (and therefore weeds) at all, the cost of maintaining stone, lead bronze, glass and brick is breathtaking in a large place, and my advice to owners of big gardens is to make sure there is plenty of money or else give it back to the cows.

Few of us, I suspect, have to worry with the maintenance of great gardens, or even modest ones like Dumbarton Oaks (moddest compared to the great ones) and I allude to them only to make the point that no amount of thought and ingenuity can reduce labor to the point that a few hours a week will suffice in a big place.

Here a garden of 60 by 200 feet is thought enormous, and 40 by 100 is thought to roomy indeed. It is precisely in gardens of that size, and up to half an acre (100 by 220 feet, say) that ingenuity is called for.

In big gardens there simply has to be plenty of labor, and in tiny places, 30 by 30 feet, there is nothing to absorb the gardener's energies except racoons, neighbors and cats. The problem in Georgetown, for example, is to find something to do.

But in the small place up to a half-acre, the gardener is usually tempted to grow a border of flowers, a few roses, a bit of lawn, and to have a small greenhouse, a couple of coldframes, perhaps a small swimming pool, a badminton court and the Lord only knows what else. A place to cook - I forgot people are forever wanting a place to cook.

Here are my suggestions for such a place, where the owner has to do it all himself:

If there is lawn, do not let the grass run up to the edge of rose beds or any other place where hand-trimming will be necessary for a neat effect. Instead, let the lawn come up a grade-level band of stone or concrete (concrete need not look like a sidewalk, but may be textured, clored gray or earth color) so that on the last lap the mower rests partly on the lawn and partly on the stone.

Have as few edges to things as possible. Narrow beds have a disproportionate amount of edging: therefore a border 14 feet wide and 100 feet long (with stepping stones to get at things) are easier than a number of small beds separated by bricks or grass paths.

Have no more paths than truly necessary. One path, 6 feet wide, is best. If it is brick, It should be set in mortar. If it is flagstone, it should be set in mortar. The inexperienced person has no conception at all how many hours can be spent weeding pavement that is not set on concrete and grouted with mortar, and while on this subject, take pains with the color of the mortar. White mortar between brick, fieldstone, slate and so on looks awful. (Existing white mortar joints can be toned down by going over them with a coat of fresh mortar colored with oxides of iron or whatever other coloring agent gives the best result.) Gravel is absurd. It rarely looks good, is never comfortable, and is ideal for weeds and masochists.

Avoid intensive care projects. Nothing known to man equals a rock garden for labor.

Incredibly enough, I have twice seen rock gardens advocated as labor-saving devices, but this only proves that human perversity is boundless. Nothing in all gardening requires so much work for so little return as a rock garden. If the gardener wants lewisias and saxifrages and other rock plants, he should struggle with them in tubs or raised borders, not in a rock garden.

Greenhouses may be nice (usually they are a total mess) but the labor of keeping them up is substantial. They have heating and ventilating systems that somebody has to take care of, and it is rare that today's liberated wife will accept greenhouse chores. A greenhouse may be endlessly rewarding, but the gardener should be certain he really wants one, and if he really does, then it should be as large as possible, not as small as possible.

Avoid plants that necessarily involve mny hours' labor a year. Irises and roses, to name two, must be hand weeded and sprayed. No other flowers surpass them in beauty (and indeed no other even equals the iris, I think) but if they are to be grown at all, they should be given ideal sites (they will sulk otherwise) and high culture.

Of course there are many roses as trouble-free as a privet bush, especially the shrub roses and some climbers, though even these require pruning from tiem to time, which is torny business.

Also, such irises as the Siberians and some of the spurias will clump up and take care of themselves in borders, but the gorgeous, tall bearded irises will not, requiring the verst best of everything, including air space around them and total absence of weeds.

Even an iris fanatic like me will admit that peonies, daffodils, daylilies, and even true lilies are much less demanding than irises and roses.

If labor is short, therefore, it make sense to choose flowers that require a tenth as much time to care for.

Wide borders with shrubs (smoke bushes, fringe trees, small plums, pink loucsts, mahonias, nandinas, photinias, small junipers or yews or box, hybrid rugosa roses, yuccas, Japanese maples, azaleas, blueberries, viburnums) and clumps of bulbs like daffodils and tulips, perennials like peonies, Japanese anemones, baptisias, artemisias, poppies, and so on and on, are less work than borders of annuals or borders of those numerous perennials that must be staked, lifted, replanted, every year or two.

Before planting anything, ask yourself if you will need to stake it, tie it, prune it, spray it, and weighs its beauty against your real commitment to it. Often, one would really prefer peonies.

Gravitate always to plants that have good foliage when not in bloom. Irises, for example, have terrible foliage in summer. The handsomer the foliage of a plant, the less work in making the garden look good.

If you need a lawn mower, try to store it where you don't have to lug it half a block before you use it. A small shed, with good outdoor electrical plugs can be worth the haste of building permits, electrician's bills, and the loss of the space it occupies.Lawn mowers were invented by the devil and fiends love them.

When possible, store tools, fertilizers, stakes, etc., in the center of the garden or at both ends, rather than at one extremity. Clearly I do not mean to store oil drums of bone meal in the center of the main walk, but often a little thought will show how to cut down on general lugging of tools and suppleis.

Consider a water-lily pool as large as possible. (In all such projects, be certain to check zoning and building-permit regulations, first, not last.) Dollar for dollar and hour for hour of maintenance, the garden lily pool is the best investment of all. But never start such projects without reading books. Sheer ignorance accounts for much wasted money. There are ways to build pools that result in decades of delight. There are other ways that cost virtually as much, and which will be a constant source of repair and anxiety.

The smaller the garden and the less labor available, the more important the architecture. I do not mean marble temples with asinine gold flames sticking out the top. I do mean a wood bench of first-rate honesty and solidity, and I do mean plain arbors of sturdy lumber, given three or four coats of expensive paint, the beams and posts mortised, and so on.

Such things cost dollars, because good material is not cheap, but good proportion, solid construction (as distinct from meaningless gewgaws that seduce the innocent) are worth far more than their dollar cost. A good place to sit in the garden is worth having, and it will count strongly in the design, far more than the frumpy ornaments sometimes acquired.

On the matter of furniture outdoors, it should be weatherproof. If the chair cushions cannot take rain and sun, to hell with them. If the table has to be polished (glass) every time you set a glass or a paw on it, to hell with it. Which of the large staff of servants do we think is going to store the chair every night, or at every cloudburst, and whou is going to clean the glass top. Iron, teak, redwood, steel mesh, plastics are materials that work. I personally dislike things that look as if the Department of Interior designed them for the use of grizzly bears, but no matter whether it is oafish or elegant, at least let it be weatherproof and practical. I have been all over town and have seen excellent things at stores, reasonably priced, that will not blow over in the first wind or, on the other hand, do not look as if they came from the Black Forest via oxcart.

Keep all outlines bold, over-scaled, plain, retangular, and keep to gray, black, earth color, except in chairs, if you like to spend 50 hours a year painting them. White leaps out in a garden, but if you like the effect (and in other people's gardens it can look great) of white fences, white furniture, be prepared to paint.

Daffodils, daylilies, peonies, combined in wide borders with shrubs, and mulched against weeds, will give handsomer effects for less labor than anything else. Hostas, yuccas and wormwoods of various sorts are also superb trouble-free creatures. They do not know what stake is, and never heard of blackspot, mildew, canker, rhizome rot or any other misery. Theirs or yours.