Q&A: Why are my fall crops growing slowly?
Red Russian kale is ready to harvest as baby greens while red cabbage continues to put on size….
After the end of daylight savings time, we’re all feeling a bit more slow and quiet. If you’re noticing that your cool-season crops are also growing at a slug’s pace in the fall, you’re not alone. Middle Tennessee’s shorter days and cooler temperatures are a refreshing change after summer, but they can make growth feel slow in raised beds. Let’s dig into some common reasons for slower growth and how you can keep your garden thriving.
1. Shorter Days Mean Less Sunlight
In the fall, days grow shorter, and plants receive less sunlight—essential for photosynthesis, the engine of plant growth. Even if you’re growing cool-season crops like lettuce, carrots, or spinach, they still need adequate light to grow steadily.
What You Can Do: Make sure your raised beds are in the sunniest spot possible for the season. Removing any overhanging branches, or shifting lightweight planters to a brighter spot can help. If you planted your fall crops in the shade of summer veggies like tomatoes or okra, it may be time to get rid of those large summer plants and let the light shine on your lettuce!
2. Cooler Temperatures Slow Growth
Fall temperatures, especially in Middle Tennessee, are mild but can dip significantly at night. This cooling effect can slow down plant metabolism, particularly for young seedlings or those that were transplanted late.
What You Can Do: Consider using row covers or cloches to provide a bit of extra warmth at night. These coverings can help protect plants from drastic temperature drops and encourage more consistent growth.
3. Soil Takes Longer to Warm Up
In raised beds, soil cools faster in fall weather, which can affect root activity and nutrient uptake. Cool soil slows down a plant’s ability to absorb water and nutrients efficiently, which can hinder growth.
What You Can Do: Adding a layer of leaf mulch can help insulate the soil and retain heat a bit longer. Mulch also conserves moisture, which is helpful for maintaining steady growth.
4. Plants Are Conserving Energy for Winter Survival
Some cool-season crops naturally grow more slowly in fall as they prepare for winter. Plants like kale, broccoli, and chard tend to focus energy on root development and sturdy stems, helping them survive colder temperatures rather than pushing rapid leaf growth.
What You Can Do: Be patient and embrace slower growth as a sign of a strong, resilient plant! You’ll often find these crops are more flavorful and tender when they mature more slowly.
5. Nutrient Levels May Be Lower in Cooler Weather
As soil cools, the natural microbial and fungal activity in soil slows down, in turn slowing the release of the nutrients the support plant growth.
What You Can Do: Use a balanced, organic fertilizer in moderation if you notice signs of nutrient deficiency, like yellowing leaves. Avoid over-fertilizing, as cool-season crops don’t need as much as summer vegetables. Make a note for next year to add fresh compost when planting for fall.
A Slower Pace is Normal in Fall
In fall, plants (and humans!) naturally shift to a slower pace. While it can be a bit of an adjustment for gardeners, this slower growth can produce heartier, tastier vegetables that thrive in cooler weather. Have some patience and enjoy gardening without the constant pressure of needing to harvest and tend to your beds. Maybe you can spend a bit more time reading garden books in bed.
