Already, our annual fund-raising campaign on behalf of Children's Hospital is reminding me of some horses I've bet on.

They get out of the gate with a limp rather than a whoosh. Sometimes they make up the lost ground by the end of the race and sometimes they don't. But whichever way the final result goes, a droopy start doesn't help.

The first week of our 1990-'91 campaign is history, and I'm afraid we've done more limping than whooshing.

The first-week totals:

Grand Total to Date: $34,643.66.

Individual Donors to Date: 181.

Group Donors to Date: 76.

Each of those figures is about 30 percent below the Week One figures of a year ago. That isn't cause for lasting alarm, since no race is ever won or lost in the first furlong. But it will be cause for great concern if we don't do much, much better in the seven weeks ahead.

Now that we've headed into the final month of the year, won't you please head for your checkbook and do what Washingtonians have been doing for 42 years? The sick kids at Children's count on you. And every cent you contribute is deductible on both your federal and state tax returns.

If you're shopping for a Christmas tree, or are about to, I'm delighted to report that you can help swell our Children's coffers at the same time.

Ticonderoga Farms in Chantilly has announced that it will donate $4 to our Children's campaign for every Christmas tree it sells between now and Dec. 25. All you have to do is to give a slip of paper to the sales clerk at the time you buy your tree indicating that you want to take part in the trees-for-kids program. Ticonderoga will do the rest.

The $4-per-tree offer applies to trees purchased between Monday and Friday, from 8:30 a.m. to dusk, from now until Christmas morning. The offer also applies to trees purchased this weekend, and on the weekend of Dec. 22-23.

Many thanks to Ticonderoga for its generous offer. For further information and directions, the farm's phone number is 703-528-4620.

TO CONTRIBUTE TO THE CAMPAIGN:

Make a check or money order payable to Children's Hospital and mail it to Bob Levey, The Washington Post, Washington, D.C., 20071.