Garden tip: The water needs of redwoods

Do you need to water redwoods in your garden? The answer is probably. Of course, it depends on your microclimate. Mill Valley trees will require less watering than Novato trees.

The coastal redwood, Sequoia sempervirens, grows along the fog belt of central coastal California to the coast of Southern Oregon. Here, in its natural habitat, it receives 50 to 100 inches of rain annually. This includes fog drip! In fact, 40% of its water intake is from coastal fog.

Redwoods have a root system of shallow, wide-spreading, lateral roots.

How much water does a large redwood need in a garden setting? You can use a soaker hose to water at the tree’s drip line every three to four weeks in the summer. Watering to a depth of 18 to 24 inches should keep your tree fresh, green and free of insects and diseases.

— Katie Martin, UC Marin master gardener