Pot plant stress

Forecasters are warning of more hot days to come. During heat waves, pot plants become stressed more quickly than plants in garden beds, and your pot plants may not getting as much water as you think.
If potting mix dries out, the first sign may be complete collapse of a plant. If you water dry potting mix in the normal way with a hose or watering can, your plants may not be getting as much water as you think. This is because potting mix shrinks slightly when it dries, leaving a narrow gap between the mix and the pot. When you water, most of it runs into the gap and out through the drainage holes, leaving the mix around the roots still dry. Seedling punnets and smaller pots can be thoroughly watered by immersing the entire pot in a bucket half filled with water, or use a laundry tub if a lot of pots need reviving.
Water should come over the top of the pot. Leave the pot in the water until bubbles cease to rise. Short term immersion won’t hurt the plants. Then lift the pot allowing it to drain into the bucket or tub. This method of watering also works very well when your water supply for plants is strictly limited.
For pots too large to be immersed in a container, fill some large soft drink or juice containers and insert 2 or 3 neck down into the potting mix. Provide support if necessary and allow them to empty slowly into the mix. Re-fill the bottles and repeat watering until water is being drawn into the mix very slowly. If heat is likely to continue for some time, place some mulch or stones on the surface of the potting mix to slow evaporation.
Potting mix can become incredibly hot when pots are in full sun. During extreme heat conditions move pot plants to a cooler spot, including under trees. Grouping them together helps retain humidity around the plants and reduces water loss through the leaves.

One thought on “Pot plant stress

  1. Such great advice. I have lots of potted plants and have been dunking them ‘in the bath’, so to speak, to get them through the worst of the summer. Using mulch on the top, and grouping plants together works a treat as well.

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