Q: I have nutgrass growing around my roses. I used a Spectracide formulated to kill the nutgrass but the growth of new roses was deformed. How do I solve this problem?
A: Spectracide Weed Stop for Lawns contains 2, 4-D as an active ingredient. It is a widely used broadleaf herbicide that is labeled for use against yellow crabgrass and yellow nutgrass.
Inadvertent damage to the herbicide may result from drift, the use of a contaminated spray unit, entrainment or improper application. Great care must be taken when using any herbicide near desirable landscape plants.
The extent of damage to desirable plants can vary considerably, depending on the stage of growth, size, dosage and environmental conditions of the plant. Larger, well-established plants are more likely to survive and recover from the damage caused by herbicides, but sometimes only time will tell.
You can not take many corrective actions, but there are some things you can do that could help (and certainly will not hurt you). Prune damaged branches to stimulate new growth. Slightly until the worms lie on the ground around your roses. Make sure that your roses are not stressed by water or that they suffer from aphid infestation (use a water jet to remove the aphids from the growth tips).
Despite your best efforts, you may end up losing your rose bush. However, due to Murphy's Law, you are likely to end up with a healthy nutgrass crop.
Q: The old grass and weeds were removed in October. I had a lot of sedgegrass (nutgrass), which took me 8 months to get rid of. I aggressively used Sedgehammer and Bonide Sedge Ender to kill him. The new lawn was placed 2 weeks ago and now I can see the sedgegeant grass again along with my new lawn. How do I keep this weed under control?
A: Most herbicides will only temporarily kill the grass because this weed has a large and deep root system. The goats will not eat it. A flamethrower (not advisable in a country of fire) will only provide temporary relief, although rewarding. The only way to truly control the nutgrass is to persistently remove it as soon as it appears. Eventually, if the plant is deprived of the capacity for photosynthesis, it will die.
Q: In a recent column, he wrote about curl leaves in a lemon tree and said to avoid pruning while the population of moths is high. My question is, in Southern California, along the coast, at what time or time of year is the population of moths a problem?
A: The best time to prune your citrus fruits is immediately after the last freezing date in your area. At that time, populations of moths (and other pests) will be lower. It also minimizes the risk that a growth-induced discharge of pruning will be damaged by frost.
To find your last frost date, see the book Sunset Western Garden Book. Their area maps are much more detailed than the USDA zone maps. This is especially relevant in Southern California because we have many different climatic zones within a relatively small area.
Do you have questions about gardening? Email [email protected]
Looking for more gardening tips? Here is how to get in touch with the Master Gardener program in your area.
Los Angeles County
[email protected]; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
[email protected]; 949-809-9760; http://mgorange.ucanr.edu/
[email protected]; 951-683-6491 ext. 231; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern @ucanredu; 909-387-2182; http://mgsb.ucanr.edu/