Advice From the Help Desk of the
UC Master Gardener Program of Contra Costa County
UC Master Gardener Help Desk: I did some research to determine possible causes for the reduced production of okra in your garden this year as compared to last year. I suspect that the high daytime temperatures that we've experienced on and off throughout the summer have contributed to the reduced production. My research also indicates that temperatures above 90° F (some sources say above 95°F) can interfere with pollination of okra and cause flowers and buds to drop. You reported in your latest message that you have noticed some encouraging signs that more pods may have started forming recently, which could be the result of the cooler temperatures that we had for several successive days last week.
Of course, we also experienced high temperatures from time to time last year when you report that production was much higher. So, there may be some other factors at work. You mentioned that you were doing some supplemental watering for the okra last summer to add to what was provided by your scheduled drip system. My research did indicate that water stress can also reduce pollination rates for okra. So perhaps the reduction in watering this year has also contributed to the reduced production rate.
One other consideration could be the fertility of the soil. Too much nitrogen will encourage lots of green growth but can suppress fruit development. Also, plants need adequate phosphorous which supports blooming and fruit production. If you have a soils test kit, it might be worth checking the fertility levels of the soils in the okra bed. If phosphorous is too low, you could supply a boost with a foliar spray or soil drench of a liquid fertilizer that is high in phosphorous. Just be careful not to supply more nitrogen if the current levels are already adequate.
One other fact I learned from my research is that you can prolong the production period of okra by cutting off about 1/3 of the plant top in late summer. This pruning allows plants to send out new growth and flower and fruit for a second time in the fall.
I hope this information is useful. You are welcome to contact our Help Desk if you have further questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (TKL)
Editor's note: For more information on okra gardening, a Sonoma County MG article is recommended (click)... the pictures in this blog post came from that article.
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: firstname.lastname@example.org, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).
Garden Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: I have several citrus trees. I would like advice on why my citrus aren't producing. What's wrong? What can I do?
One possible cause of the non-fruiting could be the age of the tree. Many varieties of citrus do not produce fruit until their third year. I have a satsuma mandarin tree growing in a large container that took four years after planting to start producing. Some other citrus varieties (including, for example, Meyer lemons) may start producing at a younger age, but the fruit that is produced in the early years is often smaller than the tree will produce as it matures, and in the early years the fruit can also appear very rough and misshapen.
Another possible cause of non-fruiting could be a lack of sun or inadequate irrigation. Citrus performs best when it receives the sun for most of the day. Proper irrigation is also important. An under-watered citrus tree will produce few if any fruits. But it is also important not to overwater citrus which can also cause problems. This link from the UC Master Gardener Program of Orange County has some very good guidance on how to water citrus: http://mgorange.ucanr.edu/Edible_Plants/?uid=58&ds=530
Lack of soil fertility could also cause problems. Citrus does need to be fertilized. The Orange County MG site referenced above also has good information on how and when to fertilize citrus with guidance on how much fertilizer to use (which depends on the age and size of the trees).
Another possible cause for nonproducing citrus trees is a lack of pollination. While many citrus varieties are capable of producing fruit without bees or other pollinizers visiting the flowers, a few varieties do require cross-pollination. For example, some clementines and mandarin hybrids require cross pollination by another tree to produce fruit. (Other mandarin varieties can produce without pollinizers and commercial growers sometimes try to keep pollinizers away from the trees so that the fruit will not contain seeds.)
Finally, some citrus trees will produce well only every other year, producing a good number of fruits one year and only a few fruits (or none at all) the next year. So, if you've observed the trees for less than two full years, you may have seen them in their non-productive year.
Hopefully, with this information you can determine and correct the cause of the problem. If not, here's the type of information we would need to help focus on your particular trees.
- In what City or part of the County are the trees located?
- What varieties do you have?
- When were the trees planted? What was the size of the tree when initially planted? What is the current size?
- How many hours of sun per day do the trees receive in spring and summer months?
- How are the trees irrigated? How much water is provided and how often do you irrigate?
- Are the trees planted in the ground or in containers?
- If the trees are in the ground, what type of soil do you have (for example, is it heavy clay or are you one of the lucky souls who have more loamy soil? If the trees are in containers, what type of soil mixture was used to fill the container?
- Is the area under the canopy of the trees mulched (which helps the soil retain moisture)?
- How have you been fertilizing the trees? (frequency, amount and type of fertilizer used)
- Does the foliage on the tree look healthy? Are the leaves green or are they yellowing? If the tree does not look healthy or you have yellowing leaves, it would help to have some photos of the trees. Take some close-up shots of the leaves but also, send us some photos taken further from the trees so that we can get a better sense of the environment and the overall look of the trees. In fact, even if the trees look healthy to you, it would be helpful for us to have photos.
- Any signs of insect damage? (for example, holes in the leaves, curled leaves, sticky substances on the leaves which could be honeydew from insects, ants crawling in the tree)
- Do the trees have flowers in the spring time? (A few varieties of citrus are just starting to show signs that blossoms will appear soon; other varieties won't bloom for a few more weeks. Some varieties may bloom at other seasonal times…. Editor's note: This response was originally written in late February)
- If the trees have bloomed in past years, have you observed any bees or other pollinizers visiting the blossoms? Are there many bees or just a few?
In addition to answering these questions, feel free to add any additional observations about the tree that you think could be relevant.
We hope that this information is helpful in getting your trees in shape to produce. If not, we encourage you to provide the additional information described above so that we can focus more precisely on your particular problems.
Help Desk of the UC Master Gardener Program of Contra Costa County (tkl)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: email@example.com, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/)./span>/span>
Advice from the Help Desk of the
UC Master Gardeners of Contra Costa County
I understand that one needs male and female plants, but this one appears to have at least 5 stalks grafted together on to the root structure. With so few bees around I was concerned about getting fruit - and we had lots of flowers. Thinking I would pollinate by hand I checked the web and then tried to determine which flowers were which, but they all looked alike to me. we did get a few kiwi, but thought we should have had more from all the flowers, and it is on the drip system, though it only runs bi-weekly to save water.
Help - what should I do next year?
MGCC Help Desk Response: Thank you for contacting the Master Gardener Help Desk. It must have been disappointing to have so few kiwifruit this year.
We recommend that when the plant blooms next year, you inspect the flowers very closely. A photo and commentary is attached to help you with that identification. If you still cannot tell the difference, then you could bring some flowers into the Help Desk and we can identify them for you. If you determine that all of your flowers are female, then you should plant a separate male vine, or graft a male vine to your existing vine.
Regarding water, kiwifruit require moderate to high amounts of water, depending on the variety. If you are growing the standard fuzzy kiwi (Actinidia deliciosa), it requires a lot of summer water. Depending upon how big the plant is, it may require 100 gallons per month or more during the summer heat.
Location: Kiwifruit will tolerate part shade but prefer a sunny location where they can ramble across some type of trellising system. The vines should be protected from strong winds. Spring gusts can snap off new growth where it emerges from the canes.
Site Preparation: Kiwifruit plants need a substantial trellis, patio cover, or other permanent place to grow upon. For the trellis system, either a single wire or T-bar system can be installed. Both have a 4 inch by 4 inch redwood post of 8 feet. For the T-bar, a 2 inch by 6 inch crossarm about 4 feet long is bolted in place. Bury the post 2 feet into the ground and cement in if at all possible. At each end of the system, a cemented deadman should be in place. Run wires across the posts and anchor tautly to the deadman. When using a patio cover, no extra trellising needs to be in place. Simply run the plant up a corner post to the top and allow the plant to then form a spoke work of shoots which would resemble an umbrella.
Soils: Kiwifruit prefer somewhat acid (pH 5 - 6.5), well-drained soils that are rich in organic matter. The leaves may show nitrogen deficiency if the soil is too basic. The plants do not tolerate salty soils.
Irrigation: Kiwifruit plants need large volumes of water during the entire growing season but must also be in well-drained soils. Watering regularly in the heat of the summer is a must. Never allow a plant to undergo drought stress. Symptoms of drought stress are drooping leaves, browning of the leaves around the edges, and complete defoliation with regrowth of new shoots when the stress is continuous. More plants probably die from water related problems than any other reason.
Fertilization: Plants are heavy nitrogen feeders which should be applied in abundance during the first half of the growing season. Late season applications of nitrogen will enhance fruit size but are discouraged as the fruit then tends to store poorly. In basic soils, a citrus and avocado tree fertilizer should be broadcast about the vine and watered in well in early March. Follow up the initial fertilizing by supplemental additions to early summer. In other areas, use a high nitrogen fertilizer which contains trace elements unless it is known that the particular soil is deficient in another nutrient. Mulching with manures and/or straws is very beneficial. However, do not put the mulch directly in contact with the vine as crown rot will occur.
Pruning: For best fruit production, pruning in the winter is a must. All pruning techniques are usually based on a "cane replacement" and differ only based on the trellising method used. Kiwi vines need to be supported and this is usually done in one of three ways: single wire, 3-5 wire on a T-bar system, or onto a patio cover. In all cases, one stem is trained up to a wire at six feet and then allowed to grow along the wire. When growth ends in a "pig-tailing" of the shoot, it is cut behind the entanglement and new a shoot allowed to grow from a leaf base. After two years multiple shoots will now emerge from the lateral mainline. During the growing season, each lateral cane will send out a new shoot about 1/3 of the way from its own starting point. The next winter, prune off the older cane at the point that it connects with last summers' new shoot. Repeat this every year.
We hope that this information is helpful. Please contact us again if you have further questions or need assistance identifying the kiwi flowers.
Help Desk of the UC Master Gardeners of Contra Costa County
Note: The UC Master Gardeners of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: firstname.lastname@example.org, or on the web at http://ccmg.ucanr.edu/Ask_Us/