Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Client:  My spaghetti squash are growing like crazy but are not ripe. What can I do?

  

Picked Spaghetti Squash (Summer 2016)

(both pictures courtesy of client.)

Response from the UCMGP Help Desk:  Thank you for contacting the Master Gardener help desk with your spaghetti squash question.

Spaghetti squash is one of the winter squash varieties along with acorn, butternut and hubbard squash. They are called winter squash because although grown in summer, they can be stored unrefrigerated to be eaten in the winter.

The secret to harvesting good winter squash is patience. Even though it may be at its maximum size, the squash needs to be left on the vine until it has formed a hard shell. It's better to leave them too long than to pick them early. Wait until the stem turns brown and the shell has finished changing color before harvesting. That way you will know it is completely ripe.

When you harvest, leave a 2" stem on the squash. Store them in a dry, dark place as close to 50-60°F as possible, and your winter squash should last in storage at least 2 months.

Please let us know if you have more questions. Happy gardening!

Editor's Note:  An interesting blog post on growing spaghetti squash in the Solano County MG's blog “Under the Solano Sun” is highly recommended, especially for the comments.

Help Desk of the UC Master Gardeners Program of Contra Costa County (SEH)

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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: ccmg@ucanr.edu, 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/). 

 

Advice from the Help Desk of the
UC Master Gardeners Program of Contra Costa County 

Client: I'm having some early summer problems in my garden. I'm reluctant to use pesticides in my garden since I have several small children. Would you please provide some recommendations to either cure and/or minimize the problems:

1. Tomato plants are doing reasonably well but there are some funky looking lower leaves that I'm concerned about.
2. My roses' leaves are mottled with brown-red markings.
3. The flowering pear tree's leaves are mottled and dropping; an arborist recommended injecting a chemical into the tree to cure the problem
4. I suspect that my garden soil is too alkaline (i.e. previously tested pH@7.1). How can I test it and what can I do to reduce pH? Will just adding compost reduce pH? 

UCMGP's Help Desk Response: Thank you for the photographs, which were very helpful. Our responses follow:

Tomatoes:  Your tomato plants look mostly healthy, but do have a very common disease called early blight seen on a lower leaf. This disease is caused by a fungus, and is spread by wind and splashing water. Disease development is favored by cool, humid conditions. To reduce the spread of the disease, avoid overhead irrigation. You may want to cut off the diseased leaf at the bottom of the plant to reduce spore production. These cultural methods should be sufficient to reduce the impact of the disease on your plants. Since you have small children and are concerned about the toxicity of pesticides, you probably will not want to use any pesticides on your tomato plants. Additional information about early blight can be found here http://ipm.ucanr.edu/PMG/GARDEN/VEGES/DISEASES/tomearlyblight.html. 

Roses:  Your roses are infected with rust, another common fungal disease in our county. Rust is favored by mild, moist conditions, and is less common during hot weather. However, once a leaf has become infected, it will not recover, and many infected leaves will drop prematurely. Avoid overhead watering or splashing onto leaves. Fungicides can protect new growth but do not eradicate the fungus from leaves that are already infected. Commercial products (when labeled for the care of rose rust) as well as Neem oil should be effective as a preventive when used before infection starts. Clean up all fallen leaves and put them in your green waste container (i.e. do not add to the compost pile). Since one of your roses is almost completely defoliated, you may want to consult with a rose specialist. You can find one here: http://www.ncnhdistrict.org/CRs/districtcr.html. Rust resistant roses are available. Additional information on rusts can be found here: http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/rusts.html. 

Flowering Pear Tree:  The photograph from the flowering pear confirms that it is infected with Entomosporium, another fungus that is spread by splashing rain. http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/entomoslfspt.html. We do not think that this disease warrants fungicide treatment. I do not know what chemical the pest company was

recommending for injection, but any chemical that has systemic activity would be transported to the leaves.  The infected leaves do fall prematurely, but the tree grows a new set of leaves later. Hot dry weather protects the new leaves from infection. The fungus survives from season to season in the fallen leaves, so it is recommended to clean up all the fallen leaves and put them also in your green waste container (i.e., again do not compost). This cleanup is made easier if there is no other vegetation under the tree and the soil is left bare. The University of California says that in special cases fungicides can be applied, but neither of the UC recommended fungicides have activity when injected, only when sprayed on the leaves. Generally, we do not recommend spraying any type of pesticide on large trees, because the chemical, applied under pressure, is bound to drift onto other plants where children, pets, beneficial insects and wild animals can be exposed. Further, since this disease is mostly a cosmetic problem and not likely to kill the tree, using fungicide is hard to justify.

Soil pH:  Home test kits for soil are fairly reliable as long as the instructions are followed carefully. A pH of 7 - 7.5 is borderline satisfactory, but may go up over time because our municipal water tends to have high pH. We recommend that you wait until the plants have been harvested and then add garden sulfur to the soil in the fall according to label directions. Lowering the pH with sulfur takes time (i.e., months), so you must be patient. Adding compost will not lower the soil pH.

I hope that this information is helpful. Please do not hesitate to contact us again. Good luck on a successful summer garden.  

Editor's Notes:  It is likely that the tomato, rose, and flowering pear tree problems may have been caused by the late rains creating conditions conducive to fungus: cool, humid conditions. Warmer, drier weather should minimize these types of fungus infestations provided there is adequate air circulation and not overhead watering early evening.

Help Desk of the UC Master Gardener Program of Contra Costa County (JL)

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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: ccmg@ucanr.edu, 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/). 

 

Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa County


Thank you for contacting the Help Desk of the UC Master Gardener Program of Contra Costa County. Your recent email had three related questions:

1. Growing watermelons and tomatoes in large containers…what is the best soil composition for successful growth?
2. What type of soil is best for your tomatoes that will be grown in wine barrels in 8 hours of hot sun?
3. Your compost material has lots of worms in it. The compost will be mixed into a wine barrel in the hot sun. How can you keep the worms alive and well in wine barrels planters in full sun?

Potting Mixture For Watermelons And Tomatoes. Regarding an appropriate potting mixture for your watermelons and tomatoes, either the mixture of soil, compost and sand (plus some coconut coir for improved water retention) or the use of a commercial potting mix combined with compost and coconut coir would provide a good growing medium.

Here are some additional thoughts about each approach as well as some notes on the benefits and disadvantages of each approach.

Soil, sand, compost and coconut coir. If you use this approach, it would be best to use a loamy garden soil. Silty loam would be the best. Sandy loam could be used, but in that case you should use less sand in the mixture. Clay soils are generally avoided for watermelon culture because they drain poorly, but they can be productive if irrigated with care to prevent prolonged saturation of the root zone (a condition that favors the development of root rot pathogens) and to allow good drainage between irrigations. Adding plenty of organic matter (e.g., compost or coconut coir) would make both the clay and sandy soils more productive.

If you use garden soil, keep in mind that it can contain insects, weed seeds and disease organisms. For this reason, it would be best to heat the soil in an oven for 1 hour at 210°F to kill any bacteria, fungi, insects, or weed seeds before the soil is combined with the compost and sand.
 
This soil mixture will be heavier than the commercial potting mixture. Added weight is sometimes a disadvantage for containers. However, since the containers may become a bit top heavy if you have a good crop of large watermelons or tomatoes growing upward on a support structure, the added weight could be an advantage. If you want the planter to be lighter, you could replace the sand in the mixture with either perlite or vermiculite. Those amendments will aid in drainage just as the sand does but would produce a mixture that weighs less than one that includes sand.

tomato growing in barrel

If you use sand, be sure that it doesn't include residual salts (as could be the case if it is collected from an ocean beach). Neither watermelons nor tomatoes would grow well if the soil is too saline.

Commercial Soil Mixture Combined With Compost And Coconut Coir. Usually a commercial soil mixture does not include any actual soil, but they can still provide a very good growing medium. If you use an available commercial soiless mixture, it would probably not be necessary to add either compost or coconut coir. This commercial mixture's ingredients already include compost, and the peat moss would function in much the same way as coconut coir to improve water retention. Adding compost and coconut coir wouldn't detract but would add to the cost.
 
One disadvantage of the mixture is that it uses peat moss which is less sustainable than the coconut coir alternative. Peat comes from very slow-growing, slow rotting plants and it typically takes 1,000 years for a bog to add 1 yard to its depth. Coconut coir is a byproduct of the coconut industry and is more easily renewed than peat.

If you want to make your own potting mixture that does not include garden soil or peat moss, you can use a combination of one-third each of compost, vermiculite or perlite and coconut coir. Measure the volume of the coconut coir only after it has been soaked in water since its volume will increase significantly once it absorbs the water. I've have been regularly growing vegetables in containers for many years and always use this potting mixture. It would work well for both the tomatoes and the watermelons.

For additional information on growing watermelons, I suggest you look over the information found at:http://anrcatalog.ucanr.edu/pdf/7213.pdf . For information about growing tomatoes in containers, see http://ccmg.ucanr.edu/files/229047.pdf.

Compost Worms In Containers. In our research, there are varying opinions about the viability of worms in containers. Considering that you mentioned having worms in your containers that will be in the hot sun for 8 hours per day, the worms would not survive in this environment. They prefer moist, cool soil which might be hard to manage in your situation. However, experimentation is always a great learning experience (although maybe not for the worms). For example, you could consider using some shade protection on very hot days. Possibly you could set it up in a way that shades the container but not the plants. Also, be sure that the soil mixture has plenty of peat and/or coconut coir to help retain water.

Thank you for contacting the Help Desk. Feel free to check back with us if you have additional questions.

Help Desk of the UC Master Gardeners Program of Contra Costa County (tkl)

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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: ccmg@ucanr.edu, 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/). 

Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Client: Hello, I live in Contra Costa County and am basically a newborn to the gardening world. I want to grow fruit trees in my home "orchard". I have a “big” question: What fruits will grow well where I live and how do I grow them?

The Home OrchardHelp Desk: Thank you for contacting the UC Master Gardener Help Desk. There are many types of fruit that will grow well in our County. UC Cooperative Extension and UC Master Gardeners Program of Contra Costa have produced a December 2015 guidance document (free download), Fruit, Nut and Grape Varieties for the Contra Costa Home Orchard that lists specific varieties for you to consider that are recommended for this County. Also, be sure and establish which climate zone you reside. Climate zones are designated in the guidance document. For example, Antioch is in (Sunset) Zone 14; so be sure to choose varieties that are indicated to do well in your zone. Once you have chosen the particular fruits that you would like to grow, you should feel free to contact us again for specific information on how to plant and care for them. The best time to plant fruit trees is when they are available as bare root trees at nurseries during the late fall and winter. You also may find some still in containers at the nursery. You may also have to special order some of them, either over the internet or special order at your local nursery. Timing is important if you need to special order, so check with your nursery. You could also get a start on educating yourself about having a backyard orchard by visiting this (free) website http://homeorchard.ucanr.edu/Fruits_&_Nuts/. You may also be interested in the UC publication on the home orchard that may be at your local library or can be obtained at this link (http://anrcatalog.ucanr.edu/Details.aspx?itemNo=3485)

I hope that this information is helpful. Good luck on your “orchard”.

Help Desk of the UC Master Gardener Program of Contra Costa County

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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: ccmg@ucanr.edu, 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/).