- Author: Jeannette Warnert
The spotted lanternfly is beautiful when its wings are open, showing off a striped yellow abdomen and ruby red and black polka dot wings. But the pest could become a menace in California.
Native to China, spotted lanternflies were first introduced into the United States in 2014 when their presence was confirmed in Berks County, Penn. They have since established populations in 17 states, as far west as Illinois. Spotted lanternflies are little more than a nuisance in their native range because they evolved along with controlling factors – such as predators and microbes – that achieved a natural balance. But when they arrive in new territory, the pest multiplies quickly and becomes a threat to the production of apples, grapes, stone fruits, roses, landscape trees and timber.
The inch-long adults are like giant aphids. The pest sucks sap out of plants and trees, depleting nutrients and reducing plant vigor. While feeding, they emit waste sugars that cover plant leaves and invite fungi to grow black sooty mold, a coating that inhibits the plants' photosynthesis.
In the eastern U.S., residents say spotted lanternflies affect their quality of life and ability to enjoy the outdoors. The pest covers trees, swarms in the air and their honeydew can coat decks and playground equipment.
Potential for cross-country spread
Spotted lanternfly movement is aided by females' ability to lay their nondescript egg masses on surfaces of natural and human-made objects, such as packages sent from distribution centers, long-haul trucks, railroad containers, recreational vehicles and ordinary cars. The egg masses are covered with a waxy gray-brown coating that looks like a splash of mud.
In fact, egg masses have already entered California. UC Integrated Pest Management advisor Cindy Kron detailed the incident at a recent webinar. A large art structure on a flatbed truck was stopped at the Truckee CDFA inspection station on March 17, 2024. Because of what appeared to be SLF egg masses on the structure, it was denied entry and ultimately more than 30 viable egg masses were found. After being power washed with soap and water in Nevada, it was cleared by inspectors with the Nevada Department Agriculture.
The structure was offloaded in Sonoma County and inspected by the local ag commissioner, who found three more egg masses.
“Each of the egg masses contain from 30 to 50 eggs,” Kron said. “This structure was carrying between 990 and 1,650 SLF eggs. That is enough to start a population.”
If the SLF egg masses had not been found, the pest could have been established in agriculture-rich California, underscoring the importance of vigilant monitoring.
“We're trying to prevent introduction, but we're not perfect,” Kron said. “We need help. We need the help of farmers, gardeners, the whole population to keep this insect out.”
Another concern for California in the face of a potential SLF infestation is the abundance of tree-of-heaven, itself an exotic pest from China and spotted lanternflies' favorite host. The tree's tendency to grow rapidly and multiply quickly has resulted in its designation as a noxious weed.
UC Master Gardeners are helping map the locations of tree-of-heaven in the state so CDFA can pro-actively reduce the number of trees available for the pest.
Learn more:
One-hour webinar by UC IPM advisor Cindy Kron about spotted lanternfly
UC Master Gardeners are part of a coordinated effort to eradicate invasive tree-of-heaven
Follow proven guidelines for successful tree-of-heaven removal
- Prepared by: Terry Lewis
Tasks
- Repair damaged spots in cool-season lawns (such as tall fescue) by scratching with a rake, seeding and covering with mulch. Keep moist until the new grass seedlings are well established. Warm-season lawns like Bermuda grass will soon be entering their dormant season, so bare patches should be covered with mulch to discourage winter weeds.
- Use spent vegetable plants and summer annuals to start a compost pile.
Pruning
- Divide and thin perennials.
- Sharpen your pruning tools in preparation for fall pruning.
Fertilizing
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To avoid a flush of new growth late in the growing season, do not apply fertilizer to citrus, avocados or other frost?tender plants.
Planting
- If the weather is cool enough, plant spring bulbs and annuals.
- Annuals: calendula, Canterbury bell (Campanula), pansy (Viola).
- Perennials: catmint (Nepeta), dianthus, fortnight lily (Dietes), Lantana.
- Fruits and vegetables: broccoli, cauliflower, parsley.
- Trees, shrubs, vines: barberry (Berberis), redbud (Cercis), fringe tree (Chionanthus), chitalpa.
- Tender leafy vegetables are best planted later in the month, and even then may require daily watering until they are well established.
Enjoy now
- Annuals and perennials: fibrous begonia.
- Bulbs, corms, tubers: cyclamen.
- Trees, shrubs, vines: beautyberry (Callicarpa), bottlebrush (Callistemon), chitalpa.
- Fruits and vegetables: garlic, gourds, grapes, peaches.
- Fall color: Raywood ash (Fraxinus angustifolia), maidenhair (Ginkgo biloba).
Things to ponder
- Cover remaining tomato and pepper plants with a garden blanket to extend the harvest season into November.
- Limit the size of fall vegetable gardens to avoid over-production. Plant only the varieties that you know you will use and enjoy, or that you can share with others.
- Author: Rosie D
Are you ready for autumn to begin and be done with the heat of the summer? I am looking forward to the fall and it can start anytime in my book! However, looks like we are (still) in for warmer than “normal” temperatures for the foreseeable future.
So, what to do in the rose garden this month? Towards the middle of the month, you can lightly prune your roses. This is not the major pruning you will do in February. Instead, you can cut any spent flowers or hips to the next set of leaflets that have either five or seven leaves. (Some roses have five leaves on their leaflets and other varieties have seven.)
This is a light trim only. Prune by cutting ¼ inch to ½ inch above an outward-facing bud eye. What is a bud eye? It is the small bump found where the leaf meets the stem/cane on the rose bush. If any canes have died during this summer (hint - they are black all the way to the soil), clip those off at the base. Only trim a maximum of 1/3 of the overall size of the bush.
If you see that by trimming the bush, there will be very little foliage left on it, don't trim it at all. Leave it alone and see how the rose bush looks in the spring. Having no foliage on your rose bush is the quickest way to kill it. What typically happens is that, when a rose is cut back with no foliage on it during this time of year, the canes will turn black and the plant slowly dies. I learned this lesson the hard way, when I first started growing roses many years ago. The safest thing is to leave your roses alone if trimming them will leave no foliage on them at all.
Again, always make sure your pruning shears are sharp and clean. Wipe with an alcohol wipe between each rose bush. Don't use bleach on your pruning shear blades as it can damage them. The alcohol wipe won't, and it will kill any diseases on the blade so they don't affect your rose bushes.
If your roses are on drip irrigation, run your system in the early morning or evening (on the days we can water) to give your roses a chance to thoroughly hydrate. Check your irrigation system to see that it is operating correctly and none of the emitters are clogged. If an emitter is delivering more or less water than the other emitters on the line, change it out for a new one. That one emitter can affect the whole system. Replace it when there is a problem.
If you grow roses in pots, make sure that they are getting enough water. If the soil has pulled away from the pot, water can run through the pot but not hydrate your plant. Make sure your potting soil allows water to get to the plant. You should re-pot your roses every couple of years. The longer the soil is in a pot, the less porous it becomes in the root zone. New soil would be in order. Don't do this now. Wait and put this on your spring chore list when your rose is dormant.
Towards the middle of the September, it is time to feed your roses. You can use a rose food (8-10-8), liquid fish or seaweed fertilizer and alfalfa meal. If the fish fertilizer smells like fish and you have a lot of neighborhood cats, you may want to use the seaweed fertilizer instead.
Alfalfa meal (not the pellets which contain sugar/molasses and can attract rodents) contains a chemical called triacontanol. It will stimulate new growth in your roses. Make sure you water the bushes before you add the alfalfa meal. Add about a cup of alfalfa meal to the soil for large, established roses and about a ½ cup for large, established mini roses. Water again afterward. Never fertilize a dry or stressed plant.
If you are using an organic rose fertilizer, apply the recommended amount (it is on the label), after the 15th of the month. You can also put down some compost. Make sure you water after putting down the fertilizer. If you wish to use liquid fish/seaweed fertilizer, mix according to the package directions. You can do this every other week up until the middle of November. Then it will be time to start giving your plants a rest for a nice bloom next spring. You should have lovely blooms for Thanksgiving, and I even have had lovely blooms for Christmas (depending on the weather).
It is still important to watch out for spider mites. You can hose those off with a good blast of water and make sure to blast the underside of the leaves as well. It is still too hot to use horticultural oil. You will burn your plants.
Pumpkin Patch roses
Until next time . . . "Autumn leaves don't fall, they fly. They take their time and wander on this their only chance to soar." - Delia Owens, "Where the Crawdads Sing"
- Prepared by: Terry Lewis
“A garden is a thing of beauty and a job forever” ~ Richard Briers
Tasks
- Despite a few last very hot summer days, fall is rapidly approaching with shorter days and cooler nights. Adjust irrigation timers, as your garden requires less water.
- The cooler weather is perfect for working in the garden. Start fall cleanup.
- Deeply water fruit and nut trees. Ideally, mature fruit trees should be irrigated to a depth of 3 feet.
Pruning
- Prune and shape photinia now to avoid removing the attractive new, red foliage. Photinia can be pruned aggressively if the plant has grown too large.
- Finish dividing iris. Replant while conditions remain warm and dry, and share extra rhizomes with friends and neighbors.
Planting
- Bulbs that do not need chilling may be planted beginning this month.
- Plant winter and spring annuals and cool-weather vegetables from cell packs.
- Annuals: snapdragon (Antirrhinum), English daisy (Bellis perennis).
- Perennials: Alstroemeria, Bellflower (campanula), chrysanthemum morifolium, Geum.
- Fruits and vegetables: beets, carrots - plant from seed.
- Trees, shrubs, vines: abelia, acacia, horse chestnut (Aesculus), strawberry tree (Arbutus unedo).
Enjoy now
- Annuals and perennials: alstroemeria, yarrow (Achillea), aster, begonia.
- Bulbs, corms, tubers: canna.
- Trees, shrubs, vines: barberry (Berberis), bougainvillea, butterfly bush (Buddleia davidii).
- Fruits and vegetables: almonds, beans, corn.
- Fall color: maple (Acer), cotoneaster.
Things to ponder
- A thick layer of mulch acts as insulation. If applied while the soil is still warm (55°- 65°) it can help extend the fall growing season.
- In the absence of soaking rains, continue to deep water trees and large shrubs at least once a week.
- Author: Elinor Teague
Central Valley gardeners will be busy this fall nursing plants and trees that were severely damaged or replacing those that died during the many and long extreme summer heat spikes that scorched our valley landscapes. Last winter's heavy rain from atmospheric rivers created by the El Niño caused severe flooding that also damaged plants and trees and changed our landscapes.
The importance of enhancing soil conditions in our gardens so that the soil's drainage and water retention capacities are greatly improved cannot be overstated. Our plants and trees will have better chances for survival in the harsh weather conditions we're experiencing if the soil can hold water and nutrients longer in drought periods and if runoff is reduced during heavy rains.
Adding large amounts of organic matter to garden and agricultural soils has been shown to have a notably positive effect on soil structure. According to the USDA Natural Conservation Service, “Soil organic matter holds 10 to 1,000 times more water and nutrients than the same amount of soil minerals."
The same article also mentions that as the added amendments change the soil's structure, several other good things happen. The soil's surface is stronger and more stable which inhibits erosion by water and wind. Less erosion and less runoff reduces the amount of particles (dust, allergens, pathogens) carried into the air and into the water system.
Soils that are heavily amended with organic matter are chock full of beneficial fungi, microbes and micro-organisms, all of which play many roles in improving soil structure and health. The long thread-like hyphae that extend out from beneficial fungi help bind soil particles, attach to plant roots and draw up additional water for the plants. Beneficial fungi and micro-organisms can attack and kill off disease pathogens or out-compete them.
Amending garden soil with organic matter at every planting is a first step in improving the soil structure. Diversifying crop types, crop rotation and tilling in cover crops are additional steps which home gardeners can take even on a small scale. Bagged compost and humus are easily found at nurseries and garden centers, as are mushroom composts, earthworm castings and tree bark composts. As always, fresh and homemade is better. Homemade compost will contain much higher numbers of more active beneficial micro-organisms and fungi. Live worms would be an added bonus.
