Reviews and recommendations are unbiased and products are independently selected. Postmedia may earn an affiliate commission from purchases made through links on this page.
Q. Even though April has been unusually cold and wet, I expect we’ll have a repeat at some point of the usual months of heat and drought. When that happens, the soil in my garden dries at alarming speed. Are there ways to drought-proof plants, and can you recommend perennials and herbs that will tolerate drought?
A. The very best protection for plants against drought is a humus-rich, moisture-retentive soil. Preparing a soil before planting with generous additions of a nourishing compost, home-made or purchased, and/or well-composted manures helps to create a spongy soil that holds on to moisture.
Mulching is a useful secondary protective measure. As air and soil temperatures warm significantly, usually in late spring or early summer, give the area to be mulched a long, slow, deep watering, preferably in the early morning. Then mulch around the plants with more good quality compost or topsoil.
In vegetable plots, I top the compost mulch with a sun-deflecting material such as straw. Shallow layers of grass clippings, alone or mixed with aged sawdust or fine wood shavings, are also used as mulching materials that help to prevent the soil from losing moisture and over-heating.
Even the most drought tolerant plants need regular watering for the first year, as they develop strong root systems.
Among herbs, the most drought tolerant are the aromatic Mediterranean ones — lavender, rosemary, thyme, sage, and oregano. They thrive in warmth and full sun.
Among perennials that I know well, three are astonishingly drought tolerant: Epimedium, bigroot geranium, and red valerian.
Geranium macrorrhizum (bigroot geranium) has aromatic, felt-like leaves and pink early summer flowers that attract bees. The plants form a dense mat that suppresses weeds.
Epimedium (barrenwort, bishop’s hat) creates carpets of decorative foliage even in the shade of and amidst the roots of large trees. The spring flowers are like miniature columbines.
A patch of Centranthus ruber (red valerian) grows and flowers out of a pile of never-watered rocks in my garden.
Fragrant flowers turn decks into ‘little havens of bliss’
How to tell the difference between pansies and violas