Garden Priorities for June

The Eighth Annual Garden Faire happens today, Saturday, June 22, in Scotts Valley’s Sky Park. There’s still time to fit it into your schedule: it continues to 5:00 p.m. plus music until 7:00. Find all the info at <thegardenfaire.org>.

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Successful gardeners synchronize their work with the annual cycle of the plants. Here are some timely tasks for the month of June.

June is the ideal time to prune certain evergreen trees, particularly Arborvitae, Deodar Cedar, Hemlock, Pine, and Spruce. You could prune Atlas Cedar, Chamaecyparis, Fir, Juniper/Red Cedar, and Leyland Cypress at this time as well. This month is also the right time to pinch back the “candles” of whorl-branched conifers, e.g., pines, spruces and firs.

I have been trying to find time to prune four English Boxwoods (Buxus sempervirens ‘Suffruticosa’) in my rose garden: they are getting bigger than I like. The preferred time for that task is late winter to early spring, i.e., mid-February to about May 1st, when new growth begins. In fact, they can be pruned at any time in the Monterey Bay area, where we don’t have the prolonged cold weather that could damage freshly pruned boxwood.

It may be tempting to shear Boxwood with hedge clippers or an electric hedge trimmer, but that’s not good for the plant. Shearing can produce a formal shape but it stimulates surface growth that shades the interior of the plant, reduces air movement and interior leaf formation and leads eventually to the plant’s decline.

The better method emphasizes thinning. After removing any dead or broken branches, cut branches to open the interior of the plant to sunlight. This might create temporary gaps in the foliage, but they will fill in soon enough and the plant will be healthier for having had the opportunity to develop interior leaves.

It is important to decide why you want boxwood in your garden. If you want to achieve a formal look, or to create a topiary shape, shearing might be appropriate, but be aware of the plant’s need to have sunlight reaching its interior.

If you are more concerned with the plant’s vigorous good health, prune by thinning. This process takes more time than shearing, and yields a more natural-looking shrub that will enhance your garden in a less formal manner.

I’ll discuss other seasonal topics in future columns. The short message for rose care is (a) fertilize monthly during the summer months, and (b) respond promptly to signs of mildew, aphid, black spot or other insect or disease problems. Watch for the Rose Curculio (Rhynchites bicolor), which will punch holes through the buds of yellow and white roses. Handpick adults and destroy infested buds.

More

Here’s a link to an interesting discussion by Peter Deahl of The Pruning School, on pruning boxwood, with the emphasis on thinning rather than shearing.

From the same place, here are notes by Peter Deahl on pruning evergreens.

Reading the online advice of skilled gardeners can be helpful, but gaining hands-on experience is most valuable. Grab your pruners!