- Author: Lori Plakos
The hour of the Dahlia
August and September are when dahlia plants are at peak performance. It is also when heat encourages spider mites to attack. The damage looks as though the plants are drying out at the bottom. If you look under the infected leaves, they will feel sticky and you will find black specks.
The best practice for controlling mites is removing the infected leaves at the bottom of the plant and washing the plants with a strong spray of the hose. Using an insecticide can make the problem worse by killing the beneficial insects that feed on the mites. If you catch it in time the plant will continue to produce beautiful flowers for you, they just won't have any leaves on the lower part of the plant.
Preserving Dahlia Blooms
Bring them in the house and set them in 2-3 inches of very hot water. Use either a plastic or metal container that doesn't retain heat. I use an automatic hot water pot and get the water to boiling before filling the plastic/metal container.
Leave the blooms in this water until it has cooled and then transfer them to your vase. You can cut the discolored ends of the stems off or leave them on, it doesn't matter. This method of preserving blooms works on any woody stemmed flower.
I recommend that you change your vase water daily. You may also use a homemade flower preservative of 2 tablespoons sugar and 2 tablespoons vinegar along with a 1/4 teaspoon of bleach to a gallon of water.
Dig up your dahlia tuber about two weeks after a killing frost or November 15th, whichever comes first. Do not dig too early. Cut the stalks down to 6”. Gently lift with a spade being careful not to break the tuber necks. Wash off the tubers and let them dry, protected from the elements, for 24 hours. Ensure that they don't dry too much - our climate dries quickly.
If you have an area in your yard that will protect your tubers from winter frost you may try leaving your tubers in the ground over the winter. An area that is up against a southwest facing structure which will hold heat from the winter sun would be such a spot. For healthier, more productive plants be prepared to dig, divide and give these a winter rest every 2-3 years. You will have to experiment with this.
I'm still experimenting with this, so here is what the experts at Swan Island Dahlias say:
Use a storage medium such as slightly dampened peat moss, sand, or pet bedding material (sawdust/shavings). Tubers should be stored in crates or cardboard boxes line your boxes with 10 - 12 sheets of newspaper. Start your packing medium in the bottom and alternate layers of tubers and medium until the container is full. Never store your tubers in plastic or completely sealed containers. Store them in a cool, dry area. Ideal temperature of the storage location is 40-50 degrees. If the tubers are kept too warm they will wrinkle and shrivel, too cold they will freeze and rot. Check on your tubers thought the winter months.
- Author: Dustin Blakey
I often get asked about whether fall is a good time to prune the landscape. While the mild weather makes it attractive to work outside, it's probably a good idea to wait, but you won't usually kill a plant outright by pruning. I don't even think about pruning until late winter. (In cold winters, I have seen some winterkill on fall-pruned plants that should have been hardy, but these are usually new plants or have other issues.)
On large orchards, practicality makes the pruning season start fairly early so that the job can get done in time, but homeowners have a lot more flexibility. Don't set your pruning schedule based on what you see in the Central Valley or down south.
Here are some pruning tips for the Eastern Sierra.
Summer-flowering trees & shrubs, modern roses, and grapes: Wait as late in winter as you can bring yourself to do, but before it gets warm. It's fine to do some light pruning early on, but wait to do the final pruning. I'm lazy and only want to prune once. March works well in these parts. An advantage to waiting is you can see what was damaged during winter and remove that. Low desert folks will do this in January.
Spring-flowering ornamentals and once-blooming roses: Wait until they flower and then prune them then.
Perennials: Do not cut back the dead foliage in winter. Leave it. Pretend it's a desireable feature if you must. The foliage protects the crown and roots from freeze damage. Remove the dead stuff just before the new growth starts. Early March is probably good. This goes for ornamental grasses, too. Folks near Lone Pine and points south can do this a bit earlier.
As a couple examples, in my admittedly non-scientific trials in Arkansas (USDA Zone 7) garden mums always made it through their first winter if not pruned even without mulch, and maybe 80% made it through if they were pruned in fall. Lantana camara always survived better if I waited until it was absolutely positively dead. I always waited until spring in my yard. Whenever I hacked it back in fall, it failed to overwinter. (Always mulched this.)
Hydrangeas: Even though their name means water-lover, they are still grown in the Owens Valley. Whatever you do, don't remove those ugly, "dead" sticks. That will be spring's flowers. Wait until they have finished blooming. The only time they need pruning is if they get too big. Same reason you'd need a haircut. When I'm sure those sticks are really dead, I remove them. Usually May. Get it done before June 25.
Palms? Not too many here in Bishop but here's some info. Maybe south Inyo folks will find it useful. I've seen a lot of mis-pruned palms there.
Remember, just because you have a plant and a set of pruners, that doesn't mean the two need meet up. Most plants do not need annual pruning. Always have a reason since you can't just glue the branches back on. Homeowners with pole pruners often do more harm than good.
Big, sick, dead, ugly, dangerous, or fruit/flower management are all good reasons. Because your neighbor does it is not a good reason. Nor is having a pruner in the garage.
Contact our help line if you have questions on specifics.