Plant Doctor Archive

Planting in pots

I DON'T have room for a vegetable garden, so I'm growing lettuces, strawberries and herbs in pots. When it rains, it splashes potting mix all over the deck. Can I use white limestone chip as a mulch or will it affect my plants? If I can't, would plain gravel be ok?

IN theory, limestone chip could raise soil pH, but decorative white limestone chip is unlikely to have much effect as it's harder and far less soluble than garden liming products. I would have no hesitation in using it as mulch around most plants, including your strawberries, vegetables and herbs, in pots or in the garden. You could wash it first to remove any lime dust and, to be on the safe side, avoid using it around acid-loving plants such as azaleas, ericas, kalmias and gardenias.

You can also safely achieve the same effect with other materials such as river pebbles or coarse pumice. All will not only keep your plants clean but deter weeds, conserve moisture and give your pots an attractive finish.

To maintain a fresh new look and remove unsightly algae, you could occasionally soak your pebbles or chip in a weak bleach solution (one part bleach to 20 parts water) for 20-30 minutes then rinse before putting back on your pots.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.