Should I fertilize my plants after a heat wave
It’s here – mid summer. Or should I say, it’s been here, as we’ve been feeling the heat for the past few weeks with seemingly no end in sight. In this sweltering weather, keeping the garden cool and well-watered is key to helping plants survive. July through August are generally the hottest months for us. Little precipitation this year along with the heat waves we’ve been through have only exasperated the garden situation and the latest 10 day forecast shows more 90 degree temps on the way.
One thing that is important to know though is Don’t fertilize your plants after a heat wave.
Very high soil temperatures (above 85°F) can cause plants to go semi-dormant, so they use very few nutrients while they’re in survival mode and aren’t prepared to make use of them. If you fertilize your plants while they’re stressed out from the heat, it may even damage them more. Sounds counterintuitive, right? But fertilizing stressed plants just stresses them even more.
Fertilizers fuel new growth, and a heat-stressed plant simply cannot keep up with the pressure of prpducing new leaves, foliage, and blossoms. An increase in the amount of water needed to move nutrients through a plant can also take its toll if a plant is already suffering from dry or inconsistently moist soil.
Withhold the fertilizers (or apply a weaker diluted solution) until the weather cools off a bit and your plants have a chance to recover. If, and only if, I need to give my plants a quick nutritional boost in high summer, I make sure the soil is evenly moist first (to reduce heat stress and improve absorption) and use a half-strength organic liquid fertilizer right at the root zone.
Time your watering for the morning or late afternoon.
The best time to water your garden in summer is from 5 am to 9 am—before the heat of the day sets in, giving your soil plenty of time to drink up before the water evaporates and any moisture on leaves to dry off before nightfall. Plants absorb water more readily when they’re not under heat stress—a condition that’s more likely to occur when the sun is at its peak during the afternoon.
If watering in the morning isn’t possible, the next best time—in general—is from 5 pm to 8 pm. This will depend on your local climate, as people in warmer regions will still experience pretty hot temperatures during those late afternoon hours,
Water well and water deeply.
Just like people, plants need thorough hydration during times of excess heat. This is especially true of outdoor container plants, as well as new plantings that haven’t yet established their roots.
Container plants—particularly those in smaller pots, fabric pots, clay pots, and baskets lined with coco fibers or sphagnum peat moss—are more susceptible to drying out than their in-ground counterparts. In the height of summer, these potted plants need special attention and may require watering every day or even up to three times a day.
Mulch
Apply 2-3” of our organic Cedar Valley Mulch around your plants and trees. Mulch helps retain soil moisture, suppresses weeds, and regulates soil temperature. Avoid over mulching which can impede water filtration and gas exchanges needed for healthy plant root growth.
