Why roses produce different colored blooms
Q: My white rose (JFK) has started producing red flowers. What could have caused this?
Although you can propagate your own roses via cutting, most commercially available roses have been grafted onto some kind of hardy rootstock. Grafted plants tend to mature and flower quickly because the bud or scion (the flowering part) is supported by a mature root system. This is a distinct advantage to growers since they would like to be able to sell larger, flowering plants within a short time. Depending on the rootstock, grafted roses are more resistant to disease, adverse soil conditions, or extreme temperatures.
Disadvantages of grafting include shortened life span, decreased winter hardiness, development of an ugly bulge at the graft union, and suckering. Your rose bush is sending up suckers from the rootstock. Simply prune any branches that emerge from below the graft union to ensure that your rose produces only the desired white blooms.
Q: My apple tree bloomed and leafed out nicely this spring, but now I'm seeing some wilting at many of the branch tips. What is causing this, and should I be concerned?
Fire blight is a bacterial disease that strikes many trees in the pome family - apples, pears, quince, and Asian pears. It is spread from one tree to another through bee activity. You'll notice that the discoloration and wilting start from the branch tips where flowers once were. Affected branches must be removed promptly to halt the spread of the bacteria to the rest of the tree. Unfortunately, if the blight reaches the main trunk, the tree is doomed.
Watch for fire blight strikes in the late spring and early summer, shortly after the tree has bloomed and as it is setting fruit. Prune any diseased branches at least several inches below discoloration and dispose of them in the regular trash (do not compost). After each cut, disinfect your pruners or saw by spraying with isopropyl alcohol (90%), Lysol, or bleach. I prefer alcohol or Lysol since they are non-corrosive. If you use bleach, immediately wipe the blades and apply oil when you are done.
Because life is not fair, ornamental pear trees (Callery pears) carry fire blight but are not killed by it. They bloom at the same time as good fruit trees, so bees carry the bacteria from the ornamental pears to susceptible trees. (As if I needed another reason to hate ornamental pear trees.)
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; 951-955-0170; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanr.edu; 909-387-2182; http://mgsb.ucanr.edu
Copyright 2026 Tribune Content Agency. All Rights Reserved.