Keep watering your landscape until the fall rains arrive. There is little to no rain predicted over the next week. And check out other things you may want to do in your landscape in September.

The season is changing. Fall is in the air, and nighttime temperatures are cooler. Here are some things you may want to do in your landscape in September.

Keep watering until it rains

We have not seen much rain yet this month, with little or no rain predicted in the next week, and daytime temperatures are still warm. Protect your valuable landscape plants by watering them until the fall rains arrive. Pay special attention to trees, shrubs and perennials that were planted within the last few years. They need regular water to help them develop deep roots.

Plant trees, shrubs and perennials

Fall is a great time to plant! Cooler temperatures mean less plant stress. You will also need to water less than if you planted in the spring. Fall rains should soon start, and plants need less water as temperatures cool. Your plants will have the winter season to develop deep roots, so they will be more robust and resilient next year.

Here are some lists of great fall plants. Or ask your local nursery for ideas and recommendations.

• Fall Plants, Great Plant Picks
• Native Plants for Fall Color, King County
• Fall Planting Guide, Sunset
• Expert Plant Picks for Your Fall Garden, Garden Design

Visit plant sales

This is a really good time to buy plants for your garden. The King County Master Gardener fall plant sale is this weekend! Visit the sale on Saturday, September 16, at Bellevue Botanical Garden for annuals, perennials and seedlings. Some nurseries have fall sales. Swansons Nursery and Molbak’s are both offering 30% off on trees, shrubs and perennials.

Review your landscape

Take a look at how your landscape performed this summer. Are there plants that didn’t grow well? Perhaps they are getting too much or too little sunlight. Are there others that may have grown too big for their location? Did you see signs of drought stress? It may be time to revise your landscape by moving or removing plants or updating your irrigation system. And with sales on plants, it is a good time to buy.

Add mulch!

We can’t say enough about the benefits of mulch for your landscape. A thick layer of mulch protects plants from weather extremes, reduces water needs and greatly reduces weeds. It feeds the soil, improving plant health. It also helps reduces the spread of soil-borne diseases, and it reduces erosion. Read our blog post, “Pro tips on how to mulch.”

Aerate and overseed your lawn

Aeration will help your lawn recover from the hot, dry summer weather. Aeration reduces soil compaction, improves the intake of water, fertilizer and oxygen, and more. After you aerate, you will want to overseed thin spots in the lawn, and you may want to top dress. Here are some tips.

A few more ideas

Other things you may want to do in your landscape in September:

• Plant bulbs for spring blooms.
• Plant a container near your front door or patio for fall color. Use plants such as chrysanthemums, pansies, asters, heuchera or ornamental cabbage.
• Plant vegetables for fall and winter harvest, such as hardy greens. See fall and winter growing guides from Territorial Seeds.