5 Tips for Fall Gardeners

By August 10, 2022Education, Fall Gardening

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:
    • 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