THE GRAND DESIGN for the garden began taking shape last January, within hours after the Burpee catalogue arrived in the mail. There is nothing quite as effortless as gardening by the fire on a cold winter's evening, with the children in bed and the wind howling outside. By the time the Jackson & Perkins catalogue arrived, the vegetable plot had trebled in size, ornate beds of annuals had been carved out of the tree roots all around the deck and hollyhocks rose majestically out of the sod alongside the fence. Azaleas spread out in a rainbow of color across one section of the front yard, and all that I needed to do was find something glorious for the edge of the driveway where the grass had been burned out last summer. Roses, I thought, as I leafed through the Jackson & Perkins illustrations. Roses and mums.

By March, I had spent enough cold evenings by the fire with enough garden catalogues that full-scale renovation plans had taken on a life of their own. My modest home was barely recognizable. Flower beds by the front steps that were overcome with weeds during my last pregnancy were transformed into manicured settings for bird baths. Cool water splashed in the fountain near the azalea bed. It looked terrific.

It is important to note here that in the matter of gardening, timing is everything. And in the matter of gardening and keeping one's family together, so is diplomacy. I learned this some years ago when I decided that two clematis vines I'd purchased had to be planted on what turned out to be a 95-degree day.Unaware of the reaction I was about to provoke, I stood innocently in the broiling sun, helpfully reading to my husband a set of instructions that began: "Prepare a planting hold, 2 feet deep and 2 feet wide . . ." From the Clematis Incident, I learned never to give explicit planting instructions that call for more than 1 foot of digging. Simply stand near the hole and say, "Just a little bit deeper, dear." It is, in other words, important not to tell the men who are gong to be doing the heavy work everything you have in mind at once. This scares them off and they leave home.

Timing was such that Phase One of the Tuileries had to be launched last weekend. This was guaranteed to be the most popular part of this year's project with my husband since it would cost no money. It was not, however, at all popular with my 15-year-old son since it entailed his doing the work. Specifically, the grand design called for six enormous, entrenched azaleas to be dug up from in front of the foundation spread of overgrown holly bushes. They would be replanted 6 feet in front of their previous site and spread out in a rainbow of color in front of the picture window. Since the buds were already on most of the bushes, they had to be dug up and replanted last weekend, before the rainbow of color turned into a transplant shock of wilt.

That little downpour Saturday morning was not going to get in the way of my project. Preparing the planting holes was a piece of cake. That took less than two hours and most of the mud my son traipsed into the living room on the way to the complaint center eventually came out of the carpeting.

Transplanting the bushes was another matter. Three of them wouldn't move. And of course they were the ones that had to be moved since they were growing up inside the holly. By the time my son came to the front door the third time to announce that I was (1) out of my mind and (2) cruel to children, I decided to go out and take a look. He had a point. But I had no intention of giving up easily on my garden project. So I stood in the pouring rain, wearing a huge raincoat of my husband's, offering no end of suggestions as to how to move the first bush out.

"MOTHER," announced my son, as the roots finally began to give, "this is ridiculous!"

"Well," said my husband, appearing on the front steps. "There's old blood and guts herself."

Being compared to Gen. Patton on the very first phase of my assault on the garden did not bode well. Moments later, the shovel broke.

"Now, look what you've done," said my son, looking at, of all people, me.

There are times when retreat is the better part of my valor. The choice was becoming clear: My son or my azaleas. After some thought, I reluctantly agreed that we'd leave two bushes were they were. By the end of the weekend the remaining azaleas had been transplanted and fertilized and Phase One of the grand design conceived in January was completed.

We have a new shovel and everyone is still talking to each other, and I, flushed with modest success at our first venture, am ready to tackle the construction of the rose and mum bed alongside the driveway. I appear to be alone. People in my house are muttering darkly about Mother's Projects, sounding vaguely like they did two years ago when I decided that a garden of lilacs and dogwoods would be just the thing in back.

Wait till they find out what's next.