It’s Labor Day weekend, the unofficial start of fall, with schools opening and tourists leaving Maine.

But that does not mean it is time to quit gardening. And I don’t mean raking leaves and harvesting the tomatoes, squash, cucumbers, lettuce and other vegetables that the garden will keep producing until the first frost.

Real gardeners know that September and October are the best time to get things done. It’s cooler, which makes the work easier, and there are fewer biting insects around. And there just generally seems to be more time.

Horticulturally, September is the best time to do lawn work. Lawns grow best in cool, moist weather, and that is fall. If you want to put in a new lawn, get the work done before the end of the month. The seed will just barely sprout by the time the ground freezes, but will have a head start in the spring. By June, the lawn will be green and lush.

If you just want to make the lawn better, this is the time for core aeration. To do this, you have to rent a machine that pulls dowel-shaped cores from the lawn. Afterward, you spread a fine compost on top of the lawn, letting some it sift down into the holes made by the core aerator. After that, apply some lawn seed, preferably fescue and perennial ryegrass.

Fall is the time to fertilize. Lawn fertilization should be done only when the lawn is actively going, and by September the cool weather and rains have let the grass come out if its dormancy from the dry, hot summer.

Expanding or renovating perennial and shrub gardens in the fall makes sense for a number of reasons, not the least of which is financial. Garden centers generally lower their prices on plants in the fall, so you can get more plants for the money.

In addition, the growing season is fresh in your mind. You know the areas where the garden was just a swath of green for a month during the summer. Buy some plants that will bloom during that period to give it a bit more interest.

You can also move plants. Sometimes you discover a shorter plant that is hidden by all of the plants around it. Or a plant that you put in the front of the border has grown taller than the label said it would, and is hiding the plants behind it. This is an ideal time to rearrange the garden to suit your preferences.

It also is a good time — and I say this every year — to dig and divide your perennials. The plants have grown, and many are probably crowding their neighbors. Digging and dividing will keep them in check.

All of these efforts require digging out growing plants. This is really quite easy. Figure out how far a plant’s roots extend, either by poking around with a trowel or by an educated guess. With a sharp shovel, slice a circle around the outside of the roots. Once that is done, you sometimes can just pry the entire plant out of the ground.

Sometimes you have to dig under it with a trowel. But if you are patient, you can safely remove any herbaceous perennial and quite a few shrubs.

Fall is also my favorite time for cutting back roses, especially rugosas. Put on leather gloves, a flannel shirt and a sweat shirt so your arms don’t get scratched. Wade right in and really cut them back. And pull out the weedy plants while doing it.

One other hint: If a plant is not doing well or if you just don’t like it, it is perfectly acceptable to dig it out and throw it away. Life is too short to put up with a bad plant.

I am not even talking about invasive plants that you’ll want to eradicate, although fall is the ideal time to kill those as well. If you do not believe in using the herbicide Roundup, you can dig and pull them out.

If you are willing to use Roundup, fall is the most effective and safest time to do it. In fall, the plants are pulling sap down into their roots. So if you cut the multiflora roses, bittersweet, honeysuckle, autumn olive, barberry or forsythia — just checking to see if you were paying attention — and paint the cuts with Roundup, the plant will suck the chemical right down to the roots. There is no drift from spraying, and the herbicide goes where it will do the most good.

Finally, if you want to get rid of some lawn for putting in a vegetable or perennial garden next spring, you should do that in the fall as well.

Cover the grass with newspapers, and put mulch on the top of the newspapers. Sometime in the spring, the grass will be dead, and you can till it all in.

Tom Atwell can be contacted at 791-6362 or at

tatwell@pressherald.com