Fall Lawn Repair & Overseeding in Denver
If your lawn has been stressed or damaged by the heat and drought conditions this summer, mid-August through mid-September is generally the best window for overseeding cool-season turf in the Denver area. Cooler temperatures and warm soil provide favorable conditions for seed germination and establishment. If you are considering overseeding this fall, the following steps can help improve your results while being mindful of water use:
- Prepare the lawn: Core aerate compacted areas to improve seed-to-soil contact and allow water and nutrients to reach the root zone. Mow the existing lawn slightly shorter than usual and remove excessive clippings and debris.
- Improve the soil: A thin layer of quality compost can be worked into the surface of the lawn after aerating. This can improve soil structure and help retain moisture, particularly in Colorado’s dry conditions.
- Select appropriate seed: Choose a grass seed that is compatible with your existing lawn and the amount of water available. For traditional cool-season turf, a quality Kentucky bluegrass or turf-type tall fescue blend may be appropriate. For areas where reducing irrigation is a priority, consider whether a lower-water turf such as buffalograss or another Colorado-adapted grass would be a better long-term solution.
- Water carefully: Newly seeded areas require consistent moisture for germination. The goal is to keep the seedbed consistently moist, not saturated. Short, frequent watering cycles may be necessary during germination. Once the seedlings are established, gradually reduce frequency and increase the depth of watering.
- Be mindful of water restrictions: Before overseeding, make sure you can provide the irrigation needed for successful establishment within the applicable watering restrictions and your property’s water budget. Overseeding can require more frequent irrigation during the establishment period.
- Avoid pre-emergent herbicides: Do not apply pre-emergent weed control immediately before or after overseeding because it can prevent grass seed from germinating. Newly seeded areas may require some additional weed management until the turf becomes established.
- Continue establishment watering into fall: Newly established turf needs adequate moisture as it develops its root system. However, watering should be adjusted as temperatures cool and natural precipitation increases rather than continuing a summer watering schedule.
Consider the Long-Term Solution :If a lawn has repeatedly struggled because of heat, drought, or limited irrigation, overseeding may provide only a temporary improvement. Fall can also be a good time to evaluate whether portions of the lawn could be converted to lower-water landscape areas or more drought-adapted turf.
For homeowners considering overseeding, I recommend evaluating the condition of the existing lawn, available irrigation, and expected water requirements before investing in seed and additional watering.
September Landscape Tips:
What to Plant
With the soil still warm but the night temperatures declining, now is a great time to plant! Container grown and balled and burlapped nursery stock can be planted through October. The sooner things are planted in early fall will allow more time for strong root and healthy root development.
Trees and Shrubs: Trees, shrubs and perennials settle in well and get their roots firmly anchored.
Perennials: If you’re making new beds or borders this fall or renovating existing ones, perennials can be divided or moved. Use a digging fork or shovel to lift a clump. If you’re dividing the plant, cut it in half or thirds with a quick thrust of a sharp blade.
Spring flowering bulbs:
Spring flowering bulbs need to get their roots established before subfreezing weather sets in for good. Water all bulbs in well as you plant to stimulate root growth.
What to Leave Alone:
Pruning: keep your fingers off the pruners and loppers. Perennials should be cut back or trimmed in late winter. Flowering shrubs should be pruned right after they bloom. Pruning now not only would cut off new buds that have formed but stimulate new growth, which is vulnerable to cold.
Tree limbs: An exception to the pruning rule: If you notice any limbs that vulnerable to snow damage, pedestrians or cars, deal with them now.
Roses: Roses are susceptible to late pruning and can often be killed by such treatment. Hybrid tea roses, however, will benefit from a mound of soil around the base of the plant. You can use potting soil from your patio containers.
Leaves: Although fallen leaves should be removed from walks, drives and gutters, there’s no need to rake them out of perennial gardens. Shade plants and soil beneath trees are enriched by fallen leaves. Come spring, you might want to do a bit of additional removal.
What to Clean Up
After frost, most annuals and vegetables look pretty sad. Pull them up and compost them, unless they have seed heads you want to enjoy in winter.
Tools: Give tools a thorough cleaning before you store them in a dry place for the winter. Rusty blades will benefit from steel wool, light oil and elbow grease. Fall is a good time to replace those beyond repair, as many stores will have tools on sale.
Sprinklers and hoses: Sprinkling systems need to be shut down and cleared. Hoses should be coiled and stored to prevent winter cracking. Keep one handy, however, for winter watering.
Pots: Empty soil out of pots. Store them upside down, under a tarp is preferable, or in a shed or garage. This helps prevent damage from alternate winter freezing and thawing.
Mulch: Mulching mowers are ideal for disposing of fallen leaves on your lawn. In addition, apply a ‘winterizer’ fertilizer to your lawn to ensure a quick green-up in spring.
Faucet Fixes Conserve water:
Did you know that one drip per second of water equates to 220 gallons a month? So it makes sense to stop the drops wherever we can. Take time to inspect all your outdoor faucets and connections now as we face the freezing temperatures of winter. I feel better knowing I’m averting potential problems early and doing my part to save water!