Q. I have a blue prince and princess holly, and I think they are doing fine, but I want to plant another female species (Blue Girl), since it doesn’t grow quite as big. Will the blue prince pollinate the Blue Girl, or do I need the Blue Boy also?
Thank you for your advice.
A. In order for a female plant to bear fruit, she must be in bloom at the same time as a compatible male. Thus, the named pairs are selected for bloom compatibility. In general, it is best to have at least one male of the named pair to be sure the bloom times coincide. You could try just planting the Blue Girl and see if she fruits. You can always add a Blue Boy later if needed. But keep in mind that it may be several years before a new plant is mature enough to flower and bear fruit. ‘Blue Stallion’ is a male selection that blooms over a longer period so should be a good pollinizer for any of the blue females.
Q. I have some evergreen shrubs and trees planted in front of my house that have now grown too big and are blocking the view out the windows! Is there a way to prune them back, and when is the best time?
A. Shrubby evergreens (juniper, yew, boxwood) can be pruned and may need trimmed annually to keep them in size for the location they are in. It would be wiser to select size-appropriate material in the first place, but that’s another issue! Some species, including yew and boxwood, can take fairly frequent and severe pruning and are often kept trimmed to very precise shapes. But many of us prefer the more informal, natural habit.
The best time of year for major pruning of evergreen shrubs is in late winter or early spring. Cut back to green-growing branches when deciding where to make a cut. Most evergreens do not tolerate shade, and inner or lower branches that are heavily shaded will die back. Hemlock is an exception in that it tolerates shade quite well.
Generally speaking, evergreen trees that have a natural, pyramidal shape (most pine, spruce, fir) should not be pruned at all, other than to remove dead or damaged limbs. If some size control is needed, you can pinch the “candles” of new growth in spring, which will shorten the growth of the developing branches.
But once the tree is already overgrown, there is really no good way to reduce the overall size of these trees without destroying their natural beauty. They have simply been planted in the wrong place where there is not enough room to accommodate their growth habit. Though it is difficult to convince most people, the best action is to remove those trees are replace with more size-appropriate plants.
The hemlock is also an exception to this as it tolerates pruning quite well, but, in my opinion, presents at its best in its natural form.
We have several articles online at Purdue that discuss pruning of evergreens and/or conifers. Here are some links.
Pruning Evergreen article from Purdue “Yard & Garden News”
http://www.hort.purdue.edu/ext/evergreens.html
HO-4, “Pruning Ornamental Trees and Shrubs”
http://www.hort.purdue.edu/ext/HO-4.pdf
HO-27, “Hedges”
http://www.hort.purdue.edu/ext/HO-27.pdf