There’s lots to do in the garden in September. More moderate temps make this a perfect time for planting with enough time for new plants to get established before frost. This is also a time to harvest edible plants and prepare your yard for fall.

Plant, divide & transplant

• Plant or transplant summer-blooming perennials including peonies, daylilies, poppies, iris, and phlox.
• Dig and divide established perennials that are growing beyond their assigned spaces – or ones that are dying out in the middle. Discard the dead centers and replant divisions from around the perimeter. Fist-sized pieces are fine. The exception: perennials that bloom in fall, such as mums, sedums and asters.
• Plant container-grown or balled-and-burlapped trees and shrubs. Apply Preen Mulch with Extended Control Weed Preventer to help retain soil moisture, moderate soil temperature and keep weed seeds from sprouting. Keep your newly planted stock well watered until the ground freezes.
• Order spring-flowering bulbs or purchase locally. Begin planting them at the end of the month. Planting too early can cause top growth to sprout before winter; allow four to six weeks for good root formation before ground freezes.

Tender plants

• Replace dead spring and summer annual flowers in your planters and garden beds with cool-season annuals including asters, calendula, mums, ornamental pansies, peppers, salvia and snapdragons.
• Dig tender bulbs, such as cannas, caladiums, tuberous begonias, and gladiolus, before frost. Air dry and store in dry peat moss or vermiculite.
• Bring houseplants back indoors. Houseplants that spent the summer outdoors should come back inside before night temperatures fall below 55 degrees. Some tropicals begin to suffer even when nighttime temperatures dip into the 40s, so don’t wait too long. Gradually decrease light to acclimate plants and help reduce leaf drop. Check for insects and disease before putting them with other plants.

Edible Plants

• Dig and repot herbs growing outdoors, or take cuttings to pot up and grow indoors.
• Plant cool-season veggies that mature quickly, including chard, radishes, lettuce and spinach, now for fall harvest.
• Root veggies like beets and carrots can be left to mature in the ground until after the first light frost.
• Dig onions and garlic after tops fall over and necks begin to dry.
• Harvest crops that die at the first frost before nighttime temps drop: tomatoes, peppers, cucumbers, beans, eggplants, and melons.
• Remove raspberry canes after they bear fruit.

Fall lawn care

• Apply a quality fall fertilizer to the lawn. Fall is the most important time to fertilize. It not only rejuvenates grass after summer stress but also encourages strong root growth before winter, leading to a healthier, greener lawn in the spring.
• For cool-season lawns, fall is the best time to plant grass seed. Take this opportunity to aerate or dethatch and overseed your lawn or repair dead patches using a good quality seed mixture.

Find more lawn care tips and professional quality lawn care products at GreenView.

Water

• Continue watering all perennials, shrubs, and trees if rainfall doesn't reach an inch or more every week or 10 days. It's important for plants to go into cold weather with adequate moisture.
• Water evergreens but don't be alarmed if some evergreen trees, especially white pine and arborvitae, drop needles. All evergreens shed needles at some time, but not all at once like deciduous plants do.

Begin cleanup

• Prevent new weeds. Seeds from spring weeds known as winter annuals actually sprout in late summer and early fall as temps cool off. If it’s been three or more months, reapply Preen Garden Weed Preventer in your gardens and around trees and shrubs. Preen will prevent these new weed seeds from sprouting this autumn. Preen Mulch with Extended Control Weed preventer provides double protection against new weeds. A layer of mulch robs seeds of light while the active ingredient creates a barrier that keeps weed seeds from growing.
• Start composting with a contained pile or purchased compost bin. Yard clippings, leaves, kitchen produce scraps, and more organic material can be composted and returned to the garden. Read how to keep weed seeds out of your compost.

More

• Stock up on gardening supplies before they are removed from retailers' shelves for the season. Pots, potting mixes, fertilizers, and other products may be harder to find later in the season.
• Stop pruning and fertilizing trees and shrubs. This is the beginning of their slow progression into winter dormancy. Don’t "confuse" them by doing things that trigger growth while their genes are attempting to regulate the opposite.