Mid–late summer is an excellent time to revisit the garden, review its successes and challenges and plan for fall – the season of renewal, regrowth and reimagining. Let’s look at some strategies that invite us to optimize the health and productivity of Colorado’s unique gardening season.
Tip #1 – Know When to Plant
- Denver’s first frost can occur the first week in October
- Check the maturity date (days to harvest) on the back of seed packets
- Add the time needed for germination (usually 7 – 10 days), plus another 10 days to your time to account for slower growth with decreasing daylight hours
Planting techniques:
- Plant slightly deeper than in spring to account for hot, dry soil, moistening soil prior to planting
- Water consistently, in the cool of the day
- Always water the roots and soil, not the leaves
- Mulch planting area with straw
- Spray with liquid kelp (1 tsp. kelp concentrate per quart of water)
- Consider using shade cloth attached to a wooden frame for peas, lettuce & spinach
Tip #2 – Select Varieties Wisely
- Crops either grown for a fall harvest or planted to overwinter & mature the following spring or early summer include:
- Seeds: leaf lettuces, spinach, arugula, mustard, radish, beets, peas, carrots, kohlrabi, green onions, cilantro (may overwinter to produce early spring crop)
- Transplants: broccoli, cabbage, cauliflower, kale, brussels sprouts
- Spring, early summer harvest: garlic
- Choose the variety of seed or transplant that matures in the shortest period of time
Tip #3 – Remove Crops that are No Longer Productive
- Any spring crops still standing in the garden (peas, radish, mustards, arugula, lettuce or spinach) should be removed, chopped up & used in the compost pile if not heavily infested with insects
- Renew soil prior to planting & around established crops:
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- Spread around an inch of plant–based compost (such as ‘A1 EcoGro’) on vacant plot areas & around main season crops
- Dig compost around 2” into bare areas & scratch several handfuls lightly into the soil around all remaining plants
Tip #4 – Save Space for Garlic
- Garlic is best planted in early October
- Either ‘hardneck’ (the kind that produces a flowering stalk called a ‘scape’) or ‘softneck’ (the kind usually found in grocery stores & used for garlic ‘braids’) can be planted
- Carefully separate the bulb into individual cloves, using the largest cloves for planting & smaller ones for eating
- Leave the papery skin intact & plant in compost–enriched soil, 3 – 4” deep, 4 – 5” apart in full sun
- Mulch with several inches of loose straw or chopped leaves (run over them with a lawnmower) if planting after leaf drop
- Water well several times over the winter if we don’t have adequate snow cover
Tip #5 – Plant Fall Cover Crops
- Grains such as winter rye and legumes such as hairy vetch are planted, often mixed together to cover the soil like a blanket, preventing soil erosion
- Their roots improve soil structure, opening up air channels that promote deeper rooting for subsequent crops & also provide nutrients that benefit soil microorganisms
- They can serve as habitats & food sources for beneficial insects
- They keep weed species in check by covering the soil surface & decreasing sunlight available for weed germination
Planting techniques:
- Plant by mid–late September
- Follow directions on the cover seed packet regarding amounts to plant
- Rake seed lightly into the top ¼ – ½” of soil, lightly pressing it in with a hoe
- Cover with a light layer of straw or chopped leaves
- Water
Early spring care:
- Cut down the cover crop before it reaches knee – high, leaving the top growth on the surface as a mulch & the roots in the ground.
- Wait 2 weeks for decomposition to occur prior to planting spring seeds
- Enjoy your best garden ever, knowing that you have worked to prepare fertile, moisture–retentive, biologically alive soil