California Redwood or the Sequoia sempervirens belongs to the Taxodiaceae family. Trees of this Family are large conifer trees, having huge barks. Redwoods can grow between 60 and 90 feet. California Redwood is adaptable to most climatic conditions and needs minimal caring. However, a redwood needs to be protected against some pests.
Pest: Cypress Tip Miner
This is most common pest among all coniferous trees. The adult miners grow into typical silver-colored moths. Their yellow-colored larvae feed on the young branches, destroying the growth tips.
Pruning regularly but in a controlled manner is suggested. Remove decaying foliage found near young redwoods. You can use a broad-spectrum insecticide that has high concentrations of acephate.
These pests are known to be highly damaging to young redwoods. They multiply quickly and invade the redwood’s internal structure:
Bark Beetles. These beetles are notorious for feeding on the redwood’s leaves. They often lay eggs inside the growing tips of redwoods. It is difficult to identify which bark beetle species has invaded the tree, since more than 600 are known to exist.
Shothole Borer. This beetle is common to redwoods growing at higher altitudes. The borer can hollow-out any wooden part of the tree.
Beetle/Borer Symptoms. Small holes can be seen on the bark and along with chewed-up leaves. Small, brown-colored larvae are found crawling on the leaves.
Redwoods that show considerable damage from borers or beetles have to be isolated. The affected parts have to be cut-away. Foliage surrounding the pruned areas should be sprayed with organic insecticides.
Pest: Spider Mites
The most common redwood-attacking mites are the Pacific spider mite and Strawberry-colored spider mite. They usually don’t cause widespread damage.
Maintain adequate irrigation since watered areas discourage Spider mites. You can use seasonal insecticidal treatments if a periodic mite outbreak is noticed.