Burned leaves and problematic pear trees: Questions for the Master Gardener
Q. How do I know when it’s time to pick my pears? Last year I picked them when I thought they were ripe, but they were bad (the cores were brown and mushy).
European pears need to be harvested when they are still hard. Depending on the variety, they will be ready anytime between August and October. Lift the fruit until it’s horizontal to the ground – if it pops off the tree, it’s ready to pick. Let them ripen on the counter, preferably on a towel to prevent bruising. This will usually take 7-10 days.
Alternatively, for longer-term storage, you can wrap the unripe fruit in tissue paper and store them in the refrigerator crisper drawer. When you want to eat one (or more), remove them from the refrigerator and allow to ripen on the counter for several days. They can be stored in the refrigerator for several weeks. When ripe, they will change color (usually from green to gold) and will give slightly when you press your thumb against the top of the fruit.
Asian pears can be allowed to ripen on the tree, picked, and eaten right away.
Q. My peaches had black rot at the stem end and around the pit. What would cause this?
If this occurs after a heatwave, it is most likely pit burn. This happens when the flesh heats up rapidly and prevents the fruit from ripening properly. There’s not much you can do to prevent this except perhaps use shade cloth to protect the tree.
Examine the fruit carefully and look for any signs of insect activity, particularly maggots. Beetles will deposit their eggs on the stem or blossom end of fruit. When the eggs hatch, the larvae burrow into the fruit and cause spoilage. If this is the case, you can trap the beetles using rotting fruit in an inverted cone trap like this one: https://ipm.ucanr.edu/PMG/FIG/fig-f02.html. Remove and dispose of any fallen fruit as well.
Q. After the last heatwave, many of my plants have burned leaves. Is it safe to trim these away? They are unsightly, but the interior leaves on most of my plants are just fine.
It’s tempting to trim away those brown, sad-looking leaves, but I would wait another few weeks. The outer leaves, although dead, protect the interior of the plant. We may still get hit with another heatwave, so wait until late October or November to clean them up.
This also applies to frost-damaged leaves on tender perennials (especially citrus). The outer leaves, even if they’re black and crispy, will protect the inner leaves from further frost damage. In this case you should be able to determine your area’s last frost date, after which you can safely remove the damaged foliage.
Los Angeles County
mglosangeleshelpline@ucdavis.edu; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
Orange County
ucceocmghotline@ucanr.edu; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanr.edu; 909-387-2182; http://mgsb.ucanr.edu