Fertilizing Fruit Trees and Information on Chill Hours"
Advice for the Home Gardener from the
Help Desk of the UC Master Gardeners of
Contra Costa County
Home Gardener Request: We're finally jumping into fully caring for our mini-orchard here in Mid-County. Could you please point us to a good reference book for that task... Also, we are getting acquainted with chill hours for growing and/or buying various fruit trees, especially for apple, plum and pear trees. Where can we find local info on chill hours?
CCMG Help Desk Response: Thanks for calling the UC Master Gardener Program Help Desk this morning with your questions about what and how to feed your apple, plum and pear trees and year to date chill hours for your area.
After some further thought, I'd like to suggest that you may want to complete a soil test of your orchard to see what your soil may be lacking before fertilizing your trees this spring as that will drive what and how much to feed.
I found that the UC Home Orchard: Growing Your Own Deciduous Fruit and Nut Trees book supports soil testing before adding potentially unnecessary fertilizers to your soil:
Although deciduous fruit trees require many nutrients for tree growth and fruit production, those grown in backyard settings in typical sandy loam to clay loam soils with proper irrigation rarely need to be fertilized. Nutrient deficiencies, when encountered, are generally limited to nitrogen, potassium, iron, and zinc, and on rare occasions, boron. Unless your soil has a known nutrient deficiency, regular applications of fertilizer usually are not necessary in a mature orchard.
Below is a link to a list of soil testing companies for you to choose from. When you contact one of the labs, they will give you instructions on how to take the sample and prepare it for shipping. Some of the labs listed also have helpful information on how to interpret the results including the amounts of necessary additives your soil needs. Soil testing companies: https://ucanr.edu/sites/ccmg/files/51308.pdf
Below is a link to information from the UC California Backyard Orchard website. It includes information on common elements for normal growth and amounts to feed by age of the tree rather than size: http://homeorchard.ucanr.edu/The_Big_Picture/Fertilization/
The links below include helpful seasonal information for growing fruit trees:
Apples & Pears: Calendar of Operations for Home Gardeners: http://homeorchard.ucdavis.edu/7258.pdf
Plums: Calendar of Operations for Home Gardeners: http://homeorchard.ucdavis.edu/7262.pdf
And finally, here is the link I used to find current information on chill hours in Contra Costa County. I selected the El Cerrito Weather Station for a chill hour to date and historical information:
https://ucanr.edu/chillcalc/?controller=station&action=reportresults&STATION=213
You may want to consider purchasing The UC Home Orchard: Growing Your Own Deciduous Fruit and Nut Trees book as it was developed especially for backyard orchardists, rare fruit growers, and small-scale growers. It is available through various online booksellers and through the UCANR Catalog: https://anrcatalog.ucanr.edu/
I hope you find this information helpful. Please let us know if you have any additional questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (SLH)
Notes: Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.edu/HortCoCo/ You can also subscribe to the Biog.
Advice for the Home Gardener
from the MGCC's Help Desk
MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk regarding your question about reducing the amount of rosettes on your artichoke plants. I was unable to find any UC research to indicate that thinning the rosettes would contribute to an increase in the production of artichokes.
The information I read about improving crop and taste had to do with cultural practices such as adding organic matter and ensuring proper watering for the plant. Artichoke plants do best in a 6.5-8 pH soil. They are heavy feeders and benefit from lots of organic matter. They like good drainage and generally do best in sun to partial shade. They require protection from prolonged frost. The pictures of your artichoke plants show that your plants look quite healthy.
There was one article I read through the UC Davis vegetable research that suggested during harvest season that the old bearing stalks could be removed to encourage the development of new shoots. The stalk was removed below the ground. The process was called “stumping”.
It was also interesting to read in several different UC resources that generally the life of an artichoke plant is about 5 years because the root area becomes crowded and the plants lose vigor.
If you would like more information about growing artichokes, below is a link to an article written about growing artichokes by the Sonoma County Master Gardeners.
http://sonomamg.ucanr.edu/Food_Gardening/Feature_Vegetables/Artichokes/
Good luck with your artichoke crop!
Help Desk of the UC Master Gardener Program of Contra Costa County (JRB)
Notes: Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.edu/HortCoCo/ You can also subscribe to the Biog.
Help for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Gardener's Request: Thank you for contacting the UC Master Gardener Program Help Desk about the ant pests in your recently installed raised bed vegetable garden. First off, welcome to the community of backyard vegetable gardeners. I hope you enjoy it as much as I do.
You've raised two questions—how to get rid of the ants which have moved into your garden bed and what to do about the ants that are crawling all over the Swiss chard where small black insect pests are also present… I'll start with the question about eliminating the ant colony from the garden bed and will then address the question relating to your Swiss chard.
MGCC Help Desk Response:
Eliminating the Ant Colony: It's not surprising that the ants have taken up residency in your garden bed. I'll bet you made it a fairly hospitable locale for ant colonies when you readied it for planting winter vegetables and herbs. It's a good idea to try to get the ants under control now before the colony expands further. Here's a link to a University of California website that has a significant amount of information about ants and how to manage them: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7411.html.
For your vegetable garden, I suggest that you focus on the use of bait stations. To find information on the use of baits in the referenced UC website, scroll down the page until you come to the section heading “MANAGEMENT” and then scroll a bit further to find the heading “Baits”. The bait stations contain a pesticide that attracts the ants because they consider it a food source. The ants carry the bait back to their nest where other ants also feed on it. The bait doesn't immediately kill the ants, but over a few days, the ants that consume the baits will die, eventually wiping out the colony.
As noted in the referenced Pestnote on ants, the baits can be purchased in several forms. The easiest ones to find are the small plastic bait traps or ant stakes sold at nurseries and hardware/home supply stores. But as noted in the Pestnote, using a refillable bait trap filled with liquid bait may be more effective, particularly when you will need to use the bait long enough to wipe out an entire colony. You may need to use an online source to purchase the refillable bait station and the liquid bait to fill it.
For the vegetable garden, you will probably want to use boric acid (borate or various forms of sodium borate) as the bait. Boric acid is effective to kill most kinds of ants. The Pestnote referenced above includes a table listing products by their brand names that contain boric acid or other forms of borate as the active ingredient.
- As noted in this UC website, the risks to the environment, water quality, honey bees and people and other mammals that are associated with the use of borate products are all fairly low, which would make it a good choice to use in the vegetable garden. http://ipm.ucanr.edu/TOOLS/PNAI/pnaishow.php?id=16.
- Be careful when you fill and place the bait trap so that you don't spill the liquid baits on growing vegetables and plants. But with such care, it should be fine to use in your garden.
The Swiss Chard Problem. You mentioned that the ants are galloping up and down the stems of the chard and that you have also noticed some type of insect pest that looks like small black dots on the chard. We believe that the small black insect pests that you are noticing on the chard are likely aphids. Aphids feed on plants by piercing the leaves with a piercing mouthpart and sucking sugary plant fluids from the leaves. As they feed, the aphids exude a sticky, sweet substance known as honeydew. Ants love to feed on the honeydew and that is likely what has attracted the ants to the Swiss chard.
Here's a link to UC's Pestnote about aphids: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html. As you'll see in the Pestnote, a number of beneficial insects such as the lady beetle and various types of parasitic wasps can be a big help in controlling aphid populations. Because the ants want to protect the honeydew food source, they are known to attack the beneficial insects to prevent them have destroying the aphids. So, to get rid of the aphids, you'll need to get rid of the ants. As you'll see, for garden plants such as yours, the aphids Pestnote recommends the use of ant baits to manage the ant problem.
Since it will take a while to eliminate that ant colony using baits, in the meantime you may want to use some water sprays to wash the aphids, ants and honeydew off the Swiss chard. As noted in the aphids Pestnote, most dislodged aphids won't be able to return to the plant, and their honeydew will be washed off as well. Use a spray bottle or a spray attachment attached to a hose and use a strong enough blast of water to dislodge the aphids. Using water sprays early in the day allows plants to dry off during the warmer daytime hours which will make them less susceptible to fungal diseases.
We hope that this information is helpful and that you're able to enjoy a good crop of winter veggies and get rid of the ant colony before it's time to plant your next crops. You're welcome to contact us again if you have further questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (TKL)
Notes: Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.edu/HortCoCo/ You can also subscribe to the Biog.
Client's Request: I'm a trapper in the Ag Department. We have been looking for plum bud gall mites in the county. I recently came across this plum tree with a huge growth or gall, it's 8" long and 7" wide on the underside of a branch, the tree is around 15 years old. Homeowner wants to know what it is and what should be done about it. The tree is in Pittsburg. Any ideas?
MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your question about a very large gall on this 15 year old plum tree in Pittsburg.
I believe this is a gall caused by the bacterium Agrobacterium tumefaciens commonly referred to as crown gall mite or possibly Plum Bud Gall Mite (Acalitus phloeocoptes (Nalepa)). Crown gall, as its name implies, typically appears at the crown of a plant, where the trunk enters the soil but it also can infect the main trunk and side branches. Plum trees are among a long list of plants commonly infected by crown gall including many popular home garden fruit trees (pluots, etc.).
The surface of crown galls and wood underneath is the same color as healthy bark and wood. However, when cut with a knife, crown galls are softer than normal wood and lack the typical pattern of annual growth rings. Galls can be tiny and smooth on young plants but usually are rough and sometimes massive on older trees.
Crown gall appears to have a relatively minor effect on most older plants which is the situation you found. Since this tree is 15 years old and the gall appears to encompass a major part of the main branch I would suggest leaving it be. If the distal portion of the branch starts to decline then the branch can be removed back towards the trunk thereby removing the gall.
Without further inspection of the gall here in our office, another possibility is the Plum Bud Gall Mite (Acalitus phloeocoptes (Nalepa)) which are well described in the Santa Clara County UCCE link below.
Following is a link to a UC Integrated Pest Management website that explains crown gall http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/crowngall.html
and here is a Santa Clara County UCCE link to Plum Bud Gall Mite:
http://mgsantaclara.ucanr.edu/files/300211.pdf
We could give a more conclusive response if you would bring a sample to our offices during our office hours described at the bottom of this response.
I hope your homeowner will be relieved. Good luck.
Help Desk of the UC Master Gardener Program of Contra Costa County (EDC)
Notes: Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.edu/HortCoCo/ You can also subscribe to the Biog.
Advice from the Help Desk of the UC Master Gardener Program of Contra Costa County
Client's Request: I purchased a Yellow Rainbow Beefsteak Tomato Plant at your annual sale in Walnut Creek this year. The plant has grown quite big and has about four tomatoes on the plant. They have stayed about the same size for about two weeks now and are not turning yellow — they are green. I have used organic tomato fertilizer, but it has not helped. Any suggestions?
It's hard to know why your tomato has been so slow to produce ripe tomatoes. However, Yellow Rainbow Beefsteak tomatoes are one of the slower tomatoes to start producing—some websites call them “fall producers”. The typical time for the plants to start producing is about 90 days from the time the seedlings go into the ground, so it does seem that your plant is a bit late. One possibility is that the soil where it is planted had excessive nitrogen fertilizer. When there is excess nitrogen, tomato plants often produce abundant foliage but set very few tomatoes. Next year, you might want to do a soil test before you plant your tomatoes. You can purchase an inexpensive home soils test kit at a nursery or big box store. The kit typically allows you to test levels of three principal nutrients—nitrogen, phosphorous and potassium (N, P, K). N is used by plants to produce green foliage; P helps with fruit production and K helps with roots and the overall well-being of the plant. Then use fertilizers only as needed to address any nutrient deficits.
You indicated that you used an organic tomato fertilizer. That likely included some amount of all three nutrients (and possibly other micro-nutrients such as calcium). If the plant was already growing well, it probably didn't need more nitrogen. Applying a fertilizer that added only phosphorous might have done the job. Also, you didn't say when you applied the fertilizer, but we are guessing you might have added it to help spur fruit production. If you applied it before the four tomatoes set, the fact that you now have those tomatoes on the plant may be a sign that the fertilizer application did help. As for the slow growth of the size of the tomatoes and their being slow to ripen, I think you just need to be patient. If is not uncommon for heirloom tomatoes to take several weeks to mature. I waited about six weeks after fruit set for tomatoes on one of my plants this year to finally grow to an appropriate size and ripen.
Tomatoes don't need to have insect pollinators to set fruit. Rather, the flowers are typically pollinated by wind action. If you have flowers on your plant that have not yet set fruit, try to duplicate the wind effect by gently shaking the plants once or twice a day, preferably mid-morning. Also, it may be helpful for you to know that tomatoes usually don't set fruit when daytime temperatures are more than 85 to 90 degrees. It's been somewhat cooler throughout our county in recent days (but not the last several days when this was edited and updated for posting) and hopefully, you may have had some additional fruit set then. But it's about to get hotter again for the next several days (or more likely cool again thank goodness). By early week when this blog is posted, it's supposed to be cooler again. Hopefully, at that time some additional tomatoes will set, particularly if you remember to shake the plant occasionally.
One final thought, keep track of how well all of your tomato plants produce and how much you enjoy their flavor. I typically try to plant at least one variety that has been a reliable producer in prior years to make it more likely that I'll get a steady supply of tomatoes. I re-plant slow producing varieties again only if I really thought their taste was outstanding and worth the wait and low production rate.
Hope you soon have some tasty tomatoes to harvest.
Help Desk of the UC Master Gardener Program of Contra Costa County (tkl)
Notes: Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.edu/HortCoCo/ You can also subscribe to the Blog.