Gardening with Gary

Gardening Advice from an Expert

Boxwood

Q. When is the best time to cut back boxwood shrubs and how much can they be cut. I have about eight down the front walkway, and they appear to be very old. How do I care for them? Thanks for your help.

Q. I live in zone 8. Is there a particular time of year I should prune boxwoods? The ones I have need serious pruning and shaping. Any suggestions you have will be appreciated. Thank you.

A. A double whammy, but the same concern...spreading boxwoods. At least the plants are growing well and you are not writing me to find out why they are dying!

Trim the shrubs now that the temps have risen and spring is upon us. I prefer to have them pruned either in the fall right before dormancy or in the very early spring before any new growth has appeared. I just returned from Ohio and saw that they are sprouting, so prune immediately.

Go through and shape them as desired. Feel free to trim way back. Take out 6 inches or as much as 2 feet I would say. The new growth will fill out and grow out better if you trim to good hardy strong stems. Clip out any weak stems and dead branches to give more light to the healthy ones! The more that you trim out the old and weak, the better the new growth will be, and before July I would think you would not even notice any old holes.

For future notes though, I would like to have you prune yearly, a little at a time, rather than once in a while taking out an awful lot of growth all at once. But you have catch up to do, so go for it!

Q. Is there anything you can do when your boxwoods get TOO big? I made the mistake of cutting them all the way back in the old house, and all I was left with was a very unhappy looking skeleton.

A. Once boxwoods are cut, all you can do is live with them. Add general gardening fertilizer to them every two weeks. Buy Peters, Scotts, Hyponex or whatever you like. The high first number, nitrogen, will speed up vegetative growth.

Q. I want to move my little boxwood bush, but am so confused as to when is the best time! Can you please advise me, so I do not kill it?

A. Early spring is the time for transplanting trees and shrubs in my opinion, since you should do it before they exit dormancy. Transplanting can be a traumatic experience for the plant if it has left dormancy and is fully leafed. Dormancy starts in the fall as soon as there is a good hard freeze. The plants remain dormant until weather warms in the spring. This is the time to transplant, while the plants are dormant.

You can transplant in the spring up until the plants leaf out. When their buds are green and a little swollen, you are safe to transplant, but once the leaves develop, moving the trees and shrubs should be delayed until fall since you risk leaf drop, burn and possible death from the shock.

Be sure to move the trees on a cool, gray day and plant into the new area as soon as you can, not allowing the root ball to come in long contact with the drying air or light. Water in slowing and deeply. Do not fertilize for a month to avoid root burn.

Wlandes writes~ I am interested in how to propagate Japanese boxwood. I live in California's High Desert. The boxwood I planted last year are doing well. In order to establish the design pattern I desire, I shall have to prune. Can I use any of the clippings to start new plants? If so, how? Do I cut at a special place?

A. Save only the good, strong stems, trim to 8", strip off the bottom 2" of leaves and propagate in a mixture of clean sand, perlite and vermiculite. Dip in a rooting hormone powder. Cover loosely with plastic and allow to root outside in a totally shaded, protected area.

Buxus microphylla 'Koreana': Korean boxwood - the most hardy boxwood, it grows in zones 4-8, but expect the foliage to brown in the winter. It is a low, spreading variety, growing to only 3 feet.

Here is a great site on 'Wintergreen':

http://www.mobot.org/gardeninghelp/plantfinder/codea/G400.shtml

There you will see that it states that it will not yellow as other varieties, hence its name. So get digging!