Ask a Master Gardner
Q. When should I prune roses and why?
A. Prune them now. Ideally they should be pruned in January or February but it is not too late, especially if you are at a higher elevation than Kingman. Pruning keeps the bush healthier, promotes airflow (which helps with insects and fungal diseases), removes dead canes, encourages new growth and keeps this growth under control. Open the center by removing canes and do not let the soil or leaf debris cover the crown (the crown is located just below where the canes grow out at the bottom). Prune branches just above a leaf bud and at a forty-five degree angle the same direction as the bud. If two canes cross each other, remove one of them. If you don't prune you will not have good quality roses.
Q. When should I prune perennials?
A. This is a good time to cut your perennial foliage to the ground with a few exceptions.
Russian sage, artemesia, creeping verbena and salvia need pruning when they start showing growth on last year's stems. Then prune just above the emerging foliage.
Ornamental grasses can be cut back to the new growth when sprigs of green growth appear. When the last average frost date for this area (April 12) has passed and butterfly bushes begin to show new growth, they can be pruned.
Q. When is the best time to apply horticultural oil sprays and why should we do this?
A. Once temperatures stay above freezing (late winter) these oils provide a safe and effective way to control insects. Apply before leaves or flowers show signs of breaking dormancy. They have little affect on wildlife and non-targeted insects. As with any horticultural product, be sure to read the label before using.
When applied according to instructions, oils can reduce populations of insect pests such as mites, aphids, mealy bugs and more.
Q. I can never remember what I planted in years past that did well (or not). Suggestions?
A. Keep a garden journal. It can be kept informally; sometimes detailed entries may be made daily or weekly. This is up to you. A journal helps you remember which plants provided timely foliage color or what bloomed in the past on whatever date, which tomato variety did well, what soil amendments needed to be made and much more. And, it can be a reminder of past events in your garden - good and bad.