- Author: Elinor Teague
We need to deep irrigate more frequently than the previously recommended once a month and deep irrigation must begin at least one day before temps are predicted to be above 95 to 100 degrees for several days.
Check soil moisture levels underneath large landscape trees and deep irrigate whenever the top 5 to 6 inches of soil is dry. That could be several times a month from June to October. Younger trees and bushes planted within the last three years also may need several soakings a month. Soaker hoses are the most efficient and effective means of delivering deep slow irrigation at the outer edges of the canopy where the feeder roots lie but small oscillating sprinklers will also work. Drip emitters are not as effective. It will take at least 3 to 4 hours of slow irrigation for water to penetrate and soak the root zone.
Insufficient water is the most common cause of poor crop set and premature fruit and nut drop. Fruit and nut trees need regular deep irrigation to maintain consistently moist soil from bloom until harvest time. Citrus trees need sufficient water in spring to set fruit and regular deep irrigation in summer through fall in order to hold and produce good-sized, juicy fruit.
During heat spikes, monitor soil moisture levels under citrus trees and deep irrigate whenever the top three to four inches of soil has dried. Plan on irrigating citrus every 3 to 4 days during heat spikes in July and August and once a week during the warm fall months.
Cool-climate redwood trees have been heavily planted in the hot and arid Central Valley to provide dense shade. Often in spaces too small for the mature tree. As a common practice, redwood trees are thinned and lower branches are removed. The heavy branch structure on redwoods creates a cooler microclimate in the interior of the canopy and thinning and removing branches on redwoods exposes the trunk and bark to the hot rays of the sun and high temperatures.
In July, the inner needles on redwood trees will turn brown and fall. It's a normal process referred to as redwood dieback. The fallen needles form a thick mulch that will help cool the soil for these shallow-rooted trees and also slow evaporation. Redwoods will benefit from increased deep slow irrigation in summer.
Branch tip dieback is the earliest and most visible sign of drought-stress. Even one long-lasting heat spike without sufficient irrigation can cause tip die back on any type tree. Gusty winds now often accompany heat spikes. Dead branches can become hazardous projectiles and should be trimmed off when noticed, but corrective pruning to reshape branch scaffolding should wait until deciduous trees are dormant in late fall and winter.
- Author: Rosie D
Welcome to March! This is the time when your roses are starting to break out from dormancy. It is a good time for garden maintenance before the big flower display in April.
If you didn't do this last month, take some time and check your irrigation system to make sure it is working correctly. Make repairs if it is not. My garden is strictly on drip. Yes, I did go through every emitter to make sure it was an adequate size and working, and cleaned out the valves to make sure they were free from sediment. It is worth the time.
If your watering system isn't drip, run your sprinklers in the morning (only on days that we can water) before the day warms up. This will avoid moisture evaporating or collecting on leaves which can (during the warmer months) result in sunburn or (during the cooler months) make it favorable for fungal diseases to develop on your roses. If you have sprinklers, avoid watering in the evening or at night. This will prevent excessive ground moisture at night. Soil that is too wet can lead to unhappy roots and/or fungal diseases. Avoid watering when it is windy, so the water doesn't evaporate into the air instead of watering your roses.
If you are thinking you might want to use fungicide to prevent fungal diseases from happening, I would encourage you to wait and see if they develop. Only spray if you see fungal diseases or pests that can't be managed by any other means.
If you believe you must spray, no matter what, here are some dos and don'ts. Don't spray on a windy day. Don't spray during the late morning, afternoon or evening hours. Don't spray when bees are out (even organic sprays). Don't spray when it is over 80 degrees F as it can burn your plants. Don't spray on a rainy day or if it is going to rain the next day. Don't spray if your pets (or your neighbor's pets) are in the yard. Don't spray if your children/grandchildren/neighbors are in the yard. I cannot stress enough that spraying is serious. You must take precautions.
If you choose to spray, you can use a lime sulfur spray or a horticultural oil mixed with a dormant spray for fungal diseases. You need to wear an appropriate face mask (N95), gloves, closed-toe shoes (no sandals or slippers), and disposable coveralls or a safety suit. Yes, anytime you spray your roses for insects or diseases, it is serious business. You can hurt yourself or others if you don't. That includes organic sprays as well, such as neem oil, BT, etc. Just because something is labeled organic, doesn't mean it can't hurt you, your neighbors, pets, birds, bees, etc. Shower, including washing your hair, after spraying. Those chemicals (yes, even organic ones) need to be stored appropriately. Don't mix chemicals because you think that it will be better for the plants. Follow directions on the label. Leftover sprays and their containers need to be disposed of, appropriately. If all of this sounds like a lot of work, it is. There are alternatives!
I remove leaves that have powdery mildew, rust, etc., if I get it. New ones will grow in. Mostly, I don't get fungal diseases. That is because I try to choose disease-resistant varieties for my yard (and we generally have low humidity). I also practice shovel pruning. If the rose is a disease-ridden mess, out it goes. I grow roses for my own enjoyment and their beauty. I don't have time to baby them. Some roses do better than others in our climate. I want the ones that do well in my yard.
I clean up debris from my roses and place it in the green bin. It does not go in my compost pile. I also keep a good 3 to 4 inches of organic mulch around my roses to stop weeds in their tracks and keep my roses roots cool in summer and warm in winter. It also helps to keep my soil moist so I can water less. The mulch will eventually break down and help improve the soil in my yard. The soil in my yard left something to be desired when I first moved here. After several years, it has greatly improved due to using compost and mulch (not rubber mulch!) that eventually breaks down and improve the soil.
I attract the “good bugs” such as lady bird beetles, lacewings, etc., by planting pollinator plants in my garden. Flowering native plants such as yarrow (Achillea), California buckwheats (Eriogonum), seaside daisy (Erigeron), sticky monkey-flowers (Mimulus), tidy tips (Layia platyglossa), etc., attract the “good bugs” that will eat the “bad bugs.” Native plants are great choices. They are beautiful and they are drought tolerant. These plants also attract birds to my yard. They too will eat the “bad bugs” and they are quite amusing to watch.
If you have the space for new roses, there is still time to purchase them and get them into the ground or a large pot. I like ordering roses online from several different sources. I find a greater variety online and end up with terrific plants. Also, the people who work at these nurseries tend to know the plants they sell and can make useful recommendations about what will or won't work in my garden.
When the new growth on your roses is about 2 to 3 inches long, you can start fertilizing. I recommend a good organic rose fertilizer. It will contain micro elements that will help to improve your soil and your plant. Synthetic fertilizers do not. In reality, as I have written before, your plant doesn't care what you buy, organic or inorganic. However, organic fertilizers won't burn your plants or add salts to your soil (synthetic fertilizers are made of various salts — not the kind of salt you eat). Organic fertilizer will help to build your soil over time. As your soil improves, you will be able to use less fertilizer but have the same result.
When you apply fertilizer, make sure the soil is moist. Water before and after your application. You can also spray your roses with seaweed (kelp) fertilizer. Roses love it. It may smell for a day or two but I have smelled much worse when it comes to fertilizers.
Again, test your soil before you fertilize. Don't fertilize just to fertilize. You are wasting your hard-earned money (which you could be spending on plants!). More is not better! I have had great results with just compost and a good layer of organic mulch (not rubber mulch).
Next month…we should be seeing some beautiful spring blooms! If you can, take some time to enjoy all of the new and beautiful spring growth in your yard.
Until next time . . . "Friends are the roses of life. . . pick them carefully and avoid the thorns!" - Unknown
- Author: Elinor Teague
As of the writing of this blog at the end of January, the Fresno/Clovis/Madera region has received only 2.79 inches of rain so far this water season, less that 25 percent of the yearly average of 11.01 inches. Unless the Central Valley receives heavy rainfall this spring, we will once again be experiencing severe drought conditions. NOAA scientists have recognized a correlation between drought periods and heat spikes. As the soil in the Valley dries out and warm dry air rises, high pressure domes form over our area, which causes temperatures to rise to extreme levels. We can anticipate that the Central Valley will also experience heat spikes along with the drought this year.
Our efforts to conserve water and also maintain the health and vigor of trees and plants in our gardens should begin in earnest this month.
There are quite a few types of irrigation devices easily available to home gardeners. Lawn sprinklers include both overhead and pop-up types. Up to 60 percent of the water applied by overhead sprinklers can be lost to evaporation, runoff and overly deep irrigation. Using pop-up or ground level sprinklers can minimize water loss somewhat. During drought periods and especially during heat spikes, irrigation of lawn grasses should be stopped or at least reduced to a bare minimum.
The amount of water and the irrigation pattern applied by emitters varies by emitter type. Choosing the right rate flow for each plant size and species and the best watering pattern is a very important part of irrigation design.
All types of irrigation systems should be on timers and those timers should be adjusted often to maintain soil moisture levels to the minimum needed to keep plants alive. When heat spikes are predicted, trees and plants should be deep irrigated before the spikes occur. Smart timers that are connected to the internet as well as local weather stations can be programmed and controlled by phone apps. Digital hose end timers can be programmed to turn on several times a day on a seven-day schedule with a rain mode option. There are simpler and cheaper hose end timer models as well. The old-school manually programmable timers as well as more advanced models that are wired to an electrical source are still available.
Sources:
California Agriculture magazine, UC Agriculture and Natural Resources