Get It Growing: September in the garden

The summer is starting to give way to the shorter days of fall. September brings cooler weather and eventually seasonal rains.

For many, this is a favorite time in the garden.

If houseplants have been moved outdoors for the summer, it’s time to bring them back inside. Check pots for pests and quarantine them to treat problems as needed.

Rake deciduous tree leaves as they fall and use them to mulch flowerbeds for the winter or add them to the compost.

If you have waited to move, divide or add plants to your landscape, this is the month to start, but wait for a cool overcast day to ease the shock. Try to plant at least a month before the expected date of the first hard frost.

Don’t be tricked by a little drizzle, continue to water as usual until the rains return in adequate quantity.

Annuals

Continue to enjoy your containers by replacing tired looking annuals with pansies, violas and annual chrysanthemums. Ornamental kale, cabbage and other fall favorites, have beautiful foliage that will often last until going to seed in spring.

Bulbs, corms, rhizomes and tubers

Keep cutting dahlia blooms. Dahlia plants will keep blooming until the first hard frost. Buy spring flowering bulbs this month, while the selection is best, to plant next month. Meanwhile, store them in a cool, dry place.

Lawns

If you have an area of ornamental lawn, fertilize it after the rains begin. If needed, renovate the lawn late this month by thatching, aerating and over-seeding.

Perennials

Continue to deadhead to keep plants attractive. By the end of the month, let the old rose flowers go to hips (seeds) to help harden off plants for winter. Cut peony stems to the ground after the leaves fall. If possible, avoid moving or dividing old peonies since they prefer to stay in the same place.

Shrubs and trees

Plant new trees and shrubs and water them deeply until winter rains return. Transplant deciduous shrubs after the leaves have fallen. Do not apply any fertilizer or prune, new or older plants, since this will stimulate new growth.

Berries

Prune out second-year raspberry and blackberry canes when they have finished fruiting. Clean-up and thin the strawberry patch, removing old or crowded plants.

Remove debris around all berry plants. Apply compost/manure in fall, allowing it to breakdown before spring, and later add a layer of mulch for winter protection.

Fruit trees

To harvest apples, first determine desired ripeness. Start on the sunniest side of the tree where fruit matures first, lift the fruit and gently twist; it should release easily. Cut the apple and if the pips (seeds) are brown, the apple is ready. Pears need to be harvested when full sized but before they become soft.

Lift and twist in a similar method as apples, letting them ripen fully after being harvested.

Vegetables

It’s not too late to sow some cool weather crops such as cilantro, arugula and winter lettuce. Sow a cover crop in vegetable beds as they are emptied. Mulch beds not containing winter or cover crops.

Harvest winter squash and pumpkins (before the first hard frost) when their stems begin to shrivel and dry and when the skin can’t be pierced with your fingernail.

Tomatoes will not vine ripen once night temperatures drop. Top tomato plants early to encourage the fruit that has already set. By the end of the month start looking for green tomato recipes.

Look for next week’s “Get it Growing” column to read about hoop houses, an inexpensive way to extend your vegetable gardening season.

Controlling volunteer annuals

Deadheading annual flowers, before they set seed, will keep them looking good and blooming longer. If not deadheaded, many annuals such as poppies, cosmos and calendula (and many more) will reseed your garden with reckless abandon. To keep self-sowing annuals under control, remove all but a few of their seed pods before they have a chance to mature and scatter. When cutting back or removing annuals, be careful not to unintentionally spread seed to other parts of the garden. If desired, collect seed on a dry day and save them in paper bags. Store seeds in a cool dry place to use next spring or to share with friends.

Susan Kalmar is a Clallam County Master Gardener.