Early September is a good time to evaluate which final projects to accomplish this year in your yard and garden. Here are a few ideas for a late summer “to-do” list and advice on one project to hold for later.
If the soil in your lawn is compacted, consider core aerating it for improvement. This allows oxygen to reach the grass roots, which increases plant vigor and can help thicken up the lawn. If your lawn does looks thin, consider reseeding it after the soil cores have dried and been ground up by your mower. This creates a good base for soil-to-seed contact and better success of new seedlings. Seeding should be completed by mid-September.
Take advantage of sale prices on perennials, as September is still a good time to plant, and the earlier in the month you plant the better. Soil temperatures are warm, which allows for good root development while daytime temperatures can be cooling. Go ahead and transplant or divide most perennials to find a better spot for them or to fill in where needed. If you aren’t certain about timing with a particular plant, contact the Master Gardener Help Line, listed below, for advice.
Continue to remove fallen leaves with spots or browned-out evergreen needles from your yard. It is likely that these harbor fungal diseases which can infect the plant or tree. Never place infected plant material in your compost pile.
It is important to continue with watering to keep trees, shrubs and plants vigorous when we have dry spells. Less frequent but deep watering is always best because it encourages plants to maintain deep roots.
Late summer is not the time to trim deciduous shrubs. Pruning at this time will encourage new growth that would likely not harden off properly before winter and can be harmed by cold weather. Fall pruning can take place when leaves have turned color or have fallen off and are no longer producing food for the shrub. Especially important is to not trim a spring flowering shrub now or in the fall, as it likely has already set its flower buds for next year. Wait until next spring after it has bloomed to trim. Trim trees in February or March when trees are dormant and structure is easily seen. Evergreens should be trimmed in the spring.
Julie Moore is a Master Gardener volunteer with the University of Illinois Extension in DuPage County.