By Brent McGhie, Butte County Master Gardener, November 29, 2013
There are several advantages to planting bare-root trees: they are usually less expensive, easier for gardeners to transport, and they will grow their roots entirely into native soil (rather than having to transition from potting mix into dissimilar native soil). Also, the ideal time to plant bare-root trees is in the winter, when you have a break from the demands of other garden chores.
Bare root trees are usually available from December through February or March, but before purchasing a tree it's a good idea to select an appropriate planting site and properly prepare it. Choose a site with plenty of sun. Fruit trees need at least 6 hours of sunlight per day; if a tree does not receive enough light, it will grow more slowly and set less fruit (plus, fruit that does set may be smaller and less sweet). Fruit trees also thrive in deep, well-drained soil. If soil is compacted, an area several feet wide around the planting site should be cultivated deeply to loosen the soil for root growth. Avoid adding fertilizer or soil amendments directly to the planting hole; instead, a well-decomposed compost can be worked into the planting site before digging the hole. Finally, if hardpan is present within one and one-half to two feet below the soil surface, it must be penetrated to allow proper drainage and root growth.
Once the planting site has been prepared, it's time to select the tree. Trees with a trunk diameter between one-half and five-eighths of an inch usually become established faster than larger or smaller stock. If the root mass is visible, be sure it is well balanced, not “one-sided.” Remove any dead or damaged roots before planting. It is best to plant bare-root trees immediately after bringing them home, but if this is not possible, the roots should be covered with sawdust or compost and kept moist until planting.
To prevent the tree from settling too low in the ground, dig the planting hole no deeper than the tree's roots. To encourage root growth, the hole should be about twice as wide as the spread of the roots. If the soil contains a large amount of clay, the sides of the hole should be scored to aid outward root growth. Build a cone of soil in the center of the hole and spread the roots over the cone, with the bud union (where the tree was grafted onto the root stock) facing south west. This prevents sun-scald of the flat side of the trunk just above the bud union. Next, back-fill the hole with the same soil that was taken from it until the hole is half filled and gently firm the soil to eliminate large air pockets. Double check the planting depth, making sure the bud union is four to six inches above the soil surface. Finish filling the hole with the native soil and gently firm it once again. When properly planted, the tree's uppermost roots should be just slightly below the soil surface and the soil should slope gently away from the trunk, preventing water from accumulating there.
Thoroughly water the newly-planted tree to settle the soil around the roots. Unless the tree has been planted in wet, heavy clay soil, a basin should be built around the tree. (In clay soils, keeping the soil too wet can eliminate air spaces in the soil, “suffocating” the roots). The basin should be donut-shaped, with the tree sitting in an island of soil in the middle of the basin. Again, to discourage rot, make sure water drains away from the tree. The basin should be slightly wider than the planting hole, ensuring that the entire root area receives water. After growth has begun in spring, water the new tree once or twice per week, adjusting the schedule as needed for cool rainy periods or early hot spells.
Clear an area about 3 feet wide around the tree, eliminating weeds and grasses to keep them from competing with the tree for water and nutrients. To prevent future weed growth and conserve moisture, a layer of mulch 3 to 6 inches thick can be placed around the tree. However, to avoid crown rot, keep the mulch several inches away from the tree trunk. As a final step, remove the top of the tree by pruning back to a single trunk approximately 24 inches tall and paint the bark of the entire tree trunk with white interior latex paint diluted with water (two parts water to one part paint) as a whitewash to reflect excess heat. This prevents sunburn and the resulting invasion of wood-boring insects that can stunt or kill the new tree.
By Jeanne Lawrence, Butte County Master Gardener, August 9, 2013
Given the right conditions, some seemingly mild-mannered plants can become garden thugs, invading entire yards and even moving on to the rest of the neighborhood. We may all have heard stories about the bamboo or mint that threatened to take over a garden, but there are other potentially nasty plants lurking out there. In the interest of saving others from the anguish of dealing with unexpectedly invasive plants, our local Master Gardeners (MGs) volunteer the following tales of their own (often on-going) battles with particular members of the plant kingdom.
Violets! Their flowers are lovely, and they create a useful ground cover….and then some. One MG reports with exasperation that they “are truly a pest;” another says that they “will never be gone.” Plus they provide a handy hide-out for leafrollers, the larva of the Geshna Cannalis moth. Leafrollers literally roll themselves up in the leaves. They deform the leaves and will spread to other plants.
Morning glories have proven to be tenacious fighters in many gardens. In particular, the perennial morning glory (often labeled “Heavenly Blue” or “Blue Dawn Flower”) can cover entire buildings, and grows so fast you'd swear you could see it growing while you watched it. One Chico MG reports that it took years to eradicate it from her yard – vines were still emerging in her shady side yard more than five years after she had dug it up from the roots in an attempt to permanently dispose of it. A Durham MG had the same experience.
Another ultra-hardy self-seeder is Scabiosa (pincushion flower). One Chico MG, who has planted two types (atropurpurea and ochroleuca) says that they reseed “almost beyond control.” Because they are so attractive, she feels guilty pulling them up, but knows that, regardless, she can't really get rid of them.
Russian Sage has proven to be very invasive in the Chapmantown yard of a Chico MG, who reports that “it sends up shoots the full length of my house.” Trying to keep it contained by cutting it just encourages the plant to send up more shoots.
Shady Chico yards provide the ideal conditions for the spread of a nearly evergreen species of alstroemeria, the Peruvian Lily A. psittacina. Its dark red flowers marked with green and blotched with dark purple appear in early summer and early fall; the two-foot-tall foliage provides useful ground cover during the winter and dies back in mid-summer. But don't be fooled! Over time this alstroemeria will move into every shady area in a yard and even colonize sunnier locations. It travels by tuberous rhizomes which develop in clusters. Because it is impossible to dig up every single tuber in these clusters, the plant is impossible to eradicate. A Chico MG with a very shady yard knows she will be battling this ultra-vigorous plant for the rest of her life.
A similar story is told by a Chico MG who moved into a house whose previous owner had planted creeping fig vine all along the backyard fence. She reports that the vine has grown in between the fence boards into the yards of the neighbors on all three sides of her lot. She is in the process of removing it by cutting it down and treating the roots with herbicide, and laments that even with this on-going vigilant approach, it will take several years to get rid of it.
Up in Paradise, an MG planted one yellow flag iris (pseudacrus) ten years ago in a semi-shady location with spring water available all year. She now has an area eight feet long and four feet wide filled with these plants, which die to the ground in cold weather. “The roots are enormous,” she says, adding that “It would require a back hoe to dig them out.”
Finally, a Durham MG has been dealing with the Miner's lettuce planted by his home's previous occupant for twenty years. Initially, he says “it was so thick I couldn't mow it and had to use a weed eater,” and it still sends up a few shoots each year. He has seen this plant advertised in a seed catalog and warns “someone would have to be insane to sow it without putting it in a container.”
The bottom line: Think twice (or three times) before planting these potential garden invaders!
http://www.plantright.org/map
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74139.html
By Brent McGhie, Butte County Master Gardener, July 26, 2013
The University of California recommends the use of Integrated Pest Management (IPM) to control garden pests. The goal of IPM is to use the least harmful control method(s) that will be effective in managing a particular pest. Depending on the pest, these methods include one or more of the following: cultural controls, biological controls, mechanical and physical controls and chemical controls (pesticides). When using IPM, it is recommended that gardeners resort to the use of pesticides only as a last resort, after other control methods have been tried and found wanting.
Before using a pesticide, be certain a pest is the actual cause of the problem you are experiencing. For example, plants can be damaged by incorrect watering, poor drainage, accidental herbicide exposure, or physical damage from wind, hail, sun scorching and other weather-related factors. A decision should also be made on how much damage you are willing to tolerate. Minor surface blemishes on fruit caused by thrips are probably an acceptable alternative to pesticide use. Once it has been determined a pest is present and is causing a major problem, identify the pest and research alternative control methods. If you need help, your Butte County Master Gardeners can provide guidance in these areas. In most cases, even if a pesticide is utilized, a combination of measures will provide the best long-term control.
Once the decision to use a pesticide has been made, the next step is to choose the right pesticide. The University of California Pest Notes series is a good source of information for identifying the least toxic pesticides appropriate for a specific pest. Low toxicity pesticides include insecticidal oils and soaps as well as the microbial insecticide, Bacillus thuringiensis, which is effective against many caterpillars, but nontoxic to other animal life. Pest Notes are available from your local Master Gardener program (based at the UC Cooperative Extension Office) and online at the UC Statewide IPM Program website (http://www.ipm.ucdavis.edu/index.html)
Before purchasing a pesticide read the label to be certain the plant you plan to use it on is listed on the label. Never use pesticides designated for use on ornamental plants on plants that will be eaten unless they are also listed on the label. Also, be aware that most pesticides only control certain stages of a pest’s life cycle. For disease control it is important to remember that fungicides are preventive and, although they may slow the progress of an existing infection, they will not eliminate it. Herbicides may be pre-emergent (preventing weeds from germinating successfully), or post-emergent (designed to kill actively growing weeds). Herbicides may also be broad-spectrum (killing weeds of almost any type), or selective in the type of weeds they affect.
Whenever a pesticide is used, all instructions should be read and carefully followed. Especially critical are instructions concerning proper application and safety precautions (for example, the use of protective clothing and eyewear).
To minimize pesticide contamination of the environment, mix only what is needed for immediate use and never use more than what the directions recommend. To further limit environmental exposure, avoid widespread applications; instead, apply only to affected areas. Do not spray during windy conditions when pesticides can be blown away from their intended target. To prevent contamination of waterways, avoid spraying near storm drains, creeks, or other bodies of water. It’s important that the application dry on the target before it gets wetted by rain or irrigation. Unless otherwise specified, do not spray just before irrigating, or before rainy weather. Additionally, be aware that spraying pesticides on hard surfaces such as foundations, driveways or sidewalks increases the likelihood that they will be washed off into storm drains.
The only legal way to dispose of pesticides is to take them to a local hazardous waste disposal facility. Do not pour unused or excess material down the drain, onto the soil, into waterways, into gutters, or into the trash. However, in California it is legal for homeowners to dispose of empty pesticide containers in the trash. Before disposing, containers should be triple rinsed and the rinse water used as part of the last application. To find the location of the closest hazardous waste disposal site, call the California Environmental Hotline (1-800-253-2687), or visit the “Earth911” website.
Information in this article is based on “Pesticides: Safe and Effective Use in the Home and Landscape” at UC IPM Online (Pest Note #74126).
By Michele Carter, Butte County Master Gardener, July 12, 2013
Yellow starthistle seeds germinate from fall through spring, corresponding to the normal rainy season in California. After germinating, the plant allocates most of its resources to root growth and by late spring, roots can extend over 3 feet. The plant exists as a short rosette amongst other weeds until it begins to flower.
The foliage of this plant ranges from gray-green to blue-green; once flowering begins it can easily be identified by its bright, thistle-like yellow flowers, which have sharp spines surrounding their bases. This weed grows from 6 inches to up to 5 feet.
Yellow starthistle forms dense infestations and rapidly depletes soil moisture, preventing the establishment of other species. It is also poisonous to horses, causing a nervous disorder called “chewing disease” (nigropallidal encephalomalacia), which is fatal once symptoms develop. Horses are the only animal known to be affected – they should not be allowed to graze on yellow starthistle.
Yellow starthistle can be spread as a contaminant in grass seed and in all classes of hay, particularly grass hay. Hay used as mulch along roadsides or disturbed areas can be a source of yellow starthistle. Livestock that have fed in areas infested with yellow starthistle can be transporters of the seed.
Because the seeds germinate during the rainy season, a single cultivation after the rainy season, when soils are dry, effectively controls yellow starthistle seedlings and rosettes. Timing is critical: this cultivation must take place in late spring after the last rains but before seeds are produced.
Mowing can be used to manage starthistle. Be sure to mow well before starthistle is in full flower or has set seed. Mowing is most effective when soil moisture is low and no irrigation or rainfall follows mowing. If rain occurs after you've removed existing plants, seeds will continue to germinate and the eradication process must be repeated. Pre-emergent and post-emergent herbicides can also be helpful in controlling growth and infestation of starthistle.
Lastly, effective management of starthistle includes revegetation. Planting affected areas with desirable plants discourages starthistle regrowth by creating competition.
For information about herbicides and for photos of yellow starthistle's growth cycle, visit http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7402.html
By Michelle Ramsey, Butte County Master Gardener, June 28, 2013
If something is eating your tomato plants or your eggplants, hornworms may very well be the culprit.
Two common species of hornworms seen in the garden are the Tomato Hornworm (Manduca quinquemaculata) and the Tobacco Hornworm (Manduca sexta). They can be differentiated by how many white stripes the larvae have on each side of their bodies. Tobacco hornworm larvae have 7 diagonal stripes on each side, while the tomato hornworm larvae have 8 chevron-shaped stripes. Mature hornworm larvae can be very large, up to 4 inches long (they will most likely be the largest “caterpillar” you’ll see in your garden). Hornworms feed on blossoms, leaves and fruit and are particularly known to cause damage to tomatoes and eggplants. Damage to plants typically occurs in mid-summer (but may also be seen in late summer). In their larval stage, hornworms are green caterpillars often seen hanging upside down on the plants. They have a “horn” at the rear end of their body. In the early summer, hornworm eggs (laid singly on leaves), hatch into larva. The larvae feed on leaves for 3-4 weeks and then burrow into the ground to pupate. The pupa over-winter in the ground and then emerge as adult moths. Adult hornworm moths are strong fliers with a wingspan of up to 5 inches.
The larval form of the hornworm is the only stage that causes damage to your plants. Hornworms can be hard to find as their green coloring provides a nice camouflage for them amidst the tomato plant leaves. Foliage damage (and possibly some damage or scarring of fruit) and large droppings on the dirt under the plants are indications that hornworms are present in the garden. When the plant is shaken gently hornworms will sometimes make a clicking sound which can help you locate the intruder. Natural enemies of hornworms are the Trichogramma parasitic wasp which lays eggs in the hornworm eggs and the Hyposoter exiguae parasitic wasp which infests the hornworm larvae as a parasite.
The most common methods of hornworm management are hand-picking them off plants and/or snipping them with shears. However, if the hornworm infestation is out of control, an organic spray (Bacillus thuringiensis or Spinosad) may be applied. These sprays are effective against smaller hornworm larvae but will not destroy the natural enemies of the hornworms. Crop rotation and disking (breaking up and turning over the soil) after harvest destroys pupae in the soil, and will help prevent emergence and a repeat of the hornworm life cycle in your garden the following year.
For additional information visit:
http://www.ipm.ucdavis.edu/PMG/r783301111.html
