SUMMER'S PERFECT TIME TO PRUNE IN VALLEY.

Byline: Joshua Siskin

Summer is the season to plant and prune a variety of tropical and subtropical plants. In general, planting of any species should coincide with that species' period of rapid root growth while pruning should be done just prior to a period of new shoot growth.

In the Valley, summer is the peak growth period for both roots and shoots of many common tropical and subtropical plants. This fact will help to answer several queries received by e-mail in recent days.

Q: What is the best time of year to prune or trim a dwarf lemon tree that is 15 to 20 feet tall?

- Jeanine Reams 

West Hills

A: Summer is an excellent time to prune a lemon tree, although any time from spring to early fall would be acceptable in the Valley. Commercial lemon growers top their trees so that fruit is produced closer to the ground and can be picked without resort to extension ladders.

You are wise to prune your lemon tree away from the roof. All fruit trees should be kept six feet away from roof lines and utility wires to keep squirrels from jumping and feeding on them.

Finally, I'm sure you are aware that the lemon tree has thorns. By using a pole pruner, you can diminish the chances of being accidentally pierced.

Q: I have a weeping fig (Ficus benjamina) growing in a container indoors which is quite overgrown. On the couple of occasions when I have pruned it before, it dripped milky sap. I would appreciate any tips on pruning these plants, including time of year.

- Beverley Falconer

British Columbia 

A: Summer is the best time of year to prune the popular weeping fig. Following winter pruning, the weeping fig may go into a funk from which it is aroused only after many months of patient pleading. In Los Angeles, I have seen the foliage of weeping figs turn yellow following winter pruning and remain yellow until July or August when growth finally resumed.

Container-grown weeping figs, as well as Indian laurel (Ficus nitida) figs, should be root pruned on an annual basis. Otherwise, they become root bound and defoliate. To root prune either of these figs, cut away the outer third of the root ball and put fresh soil in the container. Your fig will regrow with newborn vigor.

There is nothing you can do about the sticky white sap that drips from the pruning cuts made on a fig tree. Fig sap causes allergenic skin reactions with some people, so wear gloves and long sleeves when pruning if this is a concern.

Q: I have this ficus planted about 3 feet from my house (concrete slab) and bordered on the other side by a concrete walk about 2 feet away. I recently was informed that these trees have aggressive and robust root systems capable of tearing up concrete and the like. Should I transplant this tree to another location?

- Dave Czerniak

A: Because of their roots, ficus trees (weeping and Indian laurel figs) should be planted no less than 10 feet from paved surfaces, although a 20- foot separation would be even better.

Have a burlap tarp at hand to wrap as large a root ball as you can remove from the ground. Dig the new planting hole before you detach the root ball. The moment the root ball is detached, wrap it tightly in the burlap and move it to the newly dug hole. Feeder roots in the upper few inches of the root ball, the ones responsible for the daily uptake of water by the tree, are the most important roots to keep intact during the transplanting procedure.

If you cannot plant immediately, soak the burlap with a hose to keep the roots hydrated until planting, which should not be delayed for more than an hour or two.