Xtremehorticulture

Xtremehorticulture of the Desert

Fall Months a Good Time to Plant Tomatoes in Las Vegas?

Leave a Comment / indeterminate vs determinate, tomato /

Q. Is it time to plant tomatoes or still too warm? My garden is a raised bed on the south side of the house. We have a shade cover for the summer. Do I need it for the winter? Tomatoes seem to be the only vegetable I have luck with. Most squash are indeterminate as well like this one. Indeterminates just keep getting longer and longer. Indeterminates are used in greenhouses and large gardens. If you want to keep it flowering through the season, get the indeterminate form.  https://www.southernliving.com/early-girl-tomato-7550728 If you are growing in a raised bed, use predominately compact or determinate forms.  https://bonnieplants.com/products/bush-early-girl-tomato https://www.burpeehomegardens.com/Vegetables/PlantDetails.aspx?plantid=5093 https://www.edenbrothers.com/products/tomato-early-girl If you want to try a variety of the traditionally indeterminate type of  ‘Early Girl’ and still have it fruit early, then try the bush or determinate form of ‘Early Girl’. It was bred for small spaces like raised beds and containers. A. If you have an indeterminate variety (keeps getting longer and producing, such as the old-fashioned indeterminate type of ‘Early Girl’) you can cut it back now for fall production. In fact, it should have been cut back in September actually when temperatures are still hot but, looking at your app, first starts to cool. But try it now. Give it a shot. Alot depends on the weather after you cut it back. Sometimes you will luck out and it stays warm through most of the winter. The compact determinate types are pulled out after they produce fruit. Indeterminate types are cut back in the fall and then pray there is good weather. Judging from its green shape, I think it will be a grape tomato, not cherry. Tomatoes are tricky in this climate. Any time the temperature gets above about 95F tomatoes have trouble setting fruit. You will continue to harvest tomatoes that set earlier when temperatures were cooler, but tomatoes stop setting fruit when air temperatures are consistently above 95°F. Tomatoes probably produced well this past year if you kept fungal diseases at bay. This past year air temperatures would drop below 95°F erratically so tomato production may have been erratic as well in some parts of the valley. That’s what we want to accomplish is the perfect slicing tomato. This tomato was grown in Northern Afghanistan when I was there. Northern Afghanistan. although dry, had humidity more like the areas around Modesto, California. Always grow a couple of tried-and-true varieties such as the compact ‘Early Girl’, ‘Patio’, ‘Celebrity’, ‘Jet Star’ and others that you have had success with in the past. Always throw in a Roma type such as ‘San Marzano’ and cherry or grape tomatoes such as ‘Sweet 100’. If you are trying a couple of “new” varieties of tomatoes, do that carefully and remember what you planted. If you are serious about growing tomatoes, evaluate its production and care for it for three or four years in a row. You always want some older tried-and-true varieties as backups. Tomato suckers can be rooted in more humid climate or in a propagation house in the desert. Otherwise they are removed to improve air circulation through the plant. Planting in the spring Between February 15 and March 15 is better most years than cutting back indeterminate types in the fall. The weather can play havoc on gardens. You may luck out and have a non-freezing winter or location. Look at your weather app and which varieties of tomatoes you planted to determine the precise timing. When to plant, the varieties to plant and soil improvement are always important when growing tomatoes. Soils that have been “fluffed up” (rototilled or spaded) warm up faster than those that haven’t. If you’re using a soil thermometer, temperatures above 55°F are good for root growth on tomatoes.

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Calcium Deficiency of Tomato and Blossom End Rot

Leave a Comment / bitter pit, blossom end rot, Calcium deficiency, corky spot, eggplant, pepper, tomato /

Q. I wanted to ask about a strange occurrence in my tomato garden. Not all, but some of my tomatoes when they ripen, have these black spots only at the bottom of the tomato crop. I just wanted to reach out and see if you could tell me about what causes or could be causing the discoloration? Blossom end rot of tomato Blossom end rot of pepper A. That is normally a physiological problem on tomatoes, peppers and some eggplant this time of year called blossom end rot. Some scientists claim it is caused by an imbalance of calcium in some of the fruit when soils are cooler. Sometimes calcium sprays can fix it. Some varieties of tomatoes show this problem more than others. This imbalance of calcium in other plants is called “bitter pit” in susceptible apples like ‘Mutsu’ and “corky spot” in susceptible pears like ‘Comice’. Bitter pit of ‘Pink Lady’ apple Corky spot of  ‘Comice’ pear             Apples and pears take regular leaf sprays of calcium as a temporary fix in them. The easiest way to fix this problem in tomatoes is to use a less susceptible variety to blossom end rot. Otherwise, it may take several sprays of a liquid calcium spray (such as calcium chloride or calcium sulfate mixed in water) to fix it. The fruit is okay to eat, it just looks odd.

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Cracks in Tomatoes

Leave a Comment / crack, cracking, cracks., tomato, tomatoes, vegetables /

Q. What causes cracks in the tomatoes near the top where the stem is? I have also seen some of my tomatoes with very deep cracks. Let me know what you can tell me about this. The types of cracks speaks volumes. Longitudinal cracks, like this one running the length of the fruit, is caused by expansion of the fruit when it is ripening. Cracking that are radial, or run around the fruit is mostly genetic. A. There are two types of cracking, longitudinal cracks (which you have) and radial cracking (which you don’t have). Yours are longitudinal cracks. Radial cracking is mostly a varietal issue. Some varieties of tomatoes show these radial cracks more than others. If you have radial cracks, grow a different variety next season. That will lessen, but not eliminate, radial cracking. This is a so-called “Heirloom” variety called ‘Caspian Pink’. It demonstrates radial cracks typical of the variety ‘Caspian Pink’. Not much you can do about it except lessen it under better conditions but the radial cracks will still be there. All type of cracks do not harm the fresh eating of these fruits unless it spoils.             Another possibility is uneven amounts of water to the fruit. These types of skin cracking causes mostly longitudinal cracks. The swelling of the fruit and then shrinking back to its original size can cause cracking because of the expanding fruit. This type of cracking (longitudinal cracks again mostly) is lessened by using a surface mulch on top of the soil. Sometimes watering differently will help.  Longitudinal cracking of the fruit by irregular watering even with a surface mulch of straw applied. If you are using surface mulch, I would recommend wood or pine shavings (like rabbit, horse, or hamster bedding). It “melts” (decomposes) into the soil easier than straw which has fibers that are tough to decompose. Straw works but is more difficult to get it to break down quickly.             You don’t need a thick layer of surface mulch but just enough to shade the ground and lessen water lost by soil surface evaporation.

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When to Plant Tomatoes

Leave a Comment / planting, tomato /

Q. When can I put tomato plants outside in the garden? We all want these, right?Putting tomato plants into the garden at the right time is critical in our hot, desert climate. They don’t set fruit when temperatures get above 95° F. They grow poorly at temperatures in the 60s. That “sweet spot” for tomato fruit set can disappear quickly in the hot desert climates, particularly after prolonged cool wet springs. A. This has been a crazy Spring! Tomato plants grow best when soils are warm and air temperatures are above 60° F and below 90°. Traditionally, our last freeze is after mid-March. Most gardeners like to get their tomato plants out earlier than this, any time after mid-February, if its warm enough. Tomato stem rot occurs on tomato plants frequently when soil temperatures are cold and tomatoes are put outside too early.             Start watching weather projections, up to a few weeks ahead, around mid-February. As soon as weather projections predict warm weather for a 2 to 3 week period after mid-February, put transplants outside and help them to adjust from the protected greenhouse to the harsher garden environment.              Put transplants in a location protected from strong wind and intense afternoon sunlight. They should get eight hours of sun every day to remain vigorous. Never plant them in the same spot in the garden year after year. Plant them in a different part of the garden each year to reduce disease problems. This tomato plant stem was buried in the garden soil. New roots were supposed to grow from the buried stem. Instead, the tomatoes them died along with the plant. The transplant was put in the garden when soils were still cold and the soil did not drain water easily. Instead, the tomato transplant developed stem rot.             Prepare the garden soil for planting while transplants acclimate. Remember, tomatoes like warm soils so garden preparation should focus on “fluffing” the soil so that it warms more quickly. Add compost to it and double dig, spade or till the soil to open it and let warm air and sunlight raise its temperature. Hot caps and wall-o-waters are sometimes used to protect tender new transplants when air temperatures are still cold and potentially freezing. Transplants are protected from freezing temperatures but unfortunately the soil temperatures are still cold. These cold soil temperatures don’t permit transplants to grow as fast as they might.             Heavy, wet soils warm slowly when temperatures are rising. Alternatively, cover these spots with clear plastic, if you have to, to trap heat and warm it more quickly. Pin the edges of the clear plastic to the soil to keep the heat trapped under it. A potentially better technique is to warm the soil first with clear plastic and plant tomato seed directly into trenches in the warmed soil. This can be done in the middle of winter. This was demonstrated at the University Orchard in North Las Vegas.             When weather projections are positive, plant tomatoes transplants into warm soil along with a pre-plant fertilizer to improve rooting. If a generous application of compost was used during garden preparation, then add only a phosphorus fertilizer to the soil surrounding the transplant. This phosphorus fertilizer could be a mineral type such as triple super phosphate or a natural phosphorus source like bone meal.

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Tomato Plants Can Be Pruned or Not, Your Choice

Leave a Comment / summer pruning, tomato /

Q. You mentioned it is possible to cut back tomatoes for a fall harvest in hot climates. How far back do you trim them? A. No cutting back of tomato is necessary but sometimes it can help invigorate a plant which has become too large and stimulate more production. Tomato is a perennial plant that can continue to grow larger and larger if there are no freezing temperatures. Tomato sucker coming from a larger stem             Tomatoes are annuals in temperate climates that have freezing weather because of the killing low temperatures. However, cutting or trimming back tomatoes to side shoots can control the size of the plant, keep it more compact, and encourage new growth that will flower and produce fruit. Tomato smaller size after summer pruning             The two key questions are when to cut them back and how. Cut them back at a time when new growth is produced during cooler temperatures that allow for fruit to set from the flowers. The magic temperature that allows fruit to set is between 90 and 95F and lower.  Tomato fruits with sunburn because of intense sunlight after pruning             These temperatures appear in the Fall, usually toward mid to late September. Therefore, cutting them back around the end of August to the first week in September should provide some new growth over 2 to 3 weeks as temperatures cool.             Timing is always a bit of a gamble because we don’t know what the temperatures will be. We can only predict them from historical fall temperatures and experience. Summer pruning tomato for size control             How to cut them back is more difficult to explain. It might be easier to tell you what you shouldn’t do. Don’t cut tomatoes back to a single stem with no side growth immediately below the cut.             Reduce the size by cutting 1/4 inch above side growth. New growth will come from leaf axles, i.e. where a side shoot is attached to a main stem. Tomato growing new side shoots or suckers lower on the stem after pruning             When you are finished cutting back a tomato plant it should look like a smaller version of the original plant with lots of side shoots still remaining. If you cut back a plant dramatically you may need to throw some shade cloth or a light colored and lightweight breathable fabric to provide to some shade and prevent sunburn to the main stems.             After cutting back a plant, lightly fertilize the soil or give it a liquid fertilizer applied to the leaves. Liquid fertilizers applied to the leaves should be done early in the morning or late in the day this time of year. It would be ideal to apply a surface mulch to the top of the soil such as straw, animal bedding, shredded newspaper or grass clippings to preserve soil moisture.

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Tomato Plants Can Be Some Are Pruned or Not, Your Choice

5 Comments / summer pruning, tomato /

Q. You mentioned it is possible to cut back tomatoes for a fall harvest in hot climates. How far back do you trim them? A. No cutting back of tomato is necessary but sometimes it can help invigorate a plant which has become too large and stimulate more production. Tomato is a perennial plant that can continue to grow larger and larger if there are no freezing temperatures. Tomato sucker coming from a larger stem             Tomatoes are annuals in temperate climates that have freezing weather because of the killing low temperatures. However, cutting or trimming back tomatoes to side shoots can control the size of the plant, keep it more compact, and encourage new growth that will flower and produce fruit. Tomato smaller size after summer pruning             The two key questions are when to cut them back and how. Cut them back at a time when new growth is produced during cooler temperatures that allow for fruit to set from the flowers. The magic temperature that allows fruit to set is between 90 and 95F and lower.  Tomato fruits with sunburn because of intense sunlight after pruning             These temperatures appear in the Fall, usually toward mid to late September. Therefore, cutting them back around the end of August to the first week in September should provide some new growth over 2 to 3 weeks as temperatures cool.             Timing is always a bit of a gamble because we don’t know what the temperatures will be. We can only predict them from historical fall temperatures and experience. Summer pruning tomato for size control             How to cut them back is more difficult to explain. It might be easier to tell you what you shouldn’t do. Don’t cut tomatoes back to a single stem with no side growth immediately below the cut.             Reduce the size by cutting 1/4 inch above side growth. New growth will come from leaf axles, i.e. where a side shoot is attached to a main stem. Tomato growing new side shoots or suckers lower on the stem after pruning             When you are finished cutting back a tomato plant it should look like a smaller version of the original plant with lots of side shoots still remaining. If you cut back a plant dramatically you may need to throw some shade cloth or a light colored and lightweight breathable fabric to provide to some shade and prevent sunburn to the main stems.             After cutting back a plant, lightly fertilize the soil or give it a liquid fertilizer applied to the leaves. Liquid fertilizers applied to the leaves should be done early in the morning or late in the day this time of year. It would be ideal to apply a surface mulch to the top of the soil such as straw, animal bedding, shredded newspaper or grass clippings to preserve soil moisture.

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New Tomato Seedling Transplants Not Growing

Leave a Comment / eggplant, Fusarium, hardening off, pepper, tomato, transitioning, transplanting seedlings, yellowing /

Q. I started seedlings in a greenhouse and transplanted them into my raised beds. but they are not growing at all. It’s been 2 weeks, and a couple have died but the rest have not even continued growing. A. Moving seedlings of hot weather plants like tomato, pepper and eggplant from a warm, still environment like a greenhouse into one with very different temperatures and wind like a garden can be quite a shock on young plants. This kind of shock will lead to short term slowing of growth and changes in plant color as well. It can also lead to disease development if you are not careful. Transplants like these tomatoes can develop problems when temperatures begin to cool. These tomatoes developed disease problems due to a combination of dirty growing conditions and hardening off for transport to the field. In this case it is thought that Fusarium may be the problem by the symptoms displayed. Sanitation and weed control would have been an important step in preventing disease problems. Plants respond to changes in the environment very differently from animals which have legs and can move to a more hospitable environment. We try to move these transplants progressively/gradually into these less hospitable environments. This is called “hardening off” a plant. This can be opening the greenhouse so that the outside environment starts mixing with the hotter greenhouse environment, moving them into a garage first with the door open for light, moving them outside into a shaded and protected environment for a couple weeks before planting them, etc. There is a transition period when the transplant will show no signs of growth while its root system begins to grow into its new environment. The larger the transplant, the greater the transplant shock or time needed for it to adjust to its new environment. However, these problems can occur if planted incorrectly: Make sure you planted transplants the same depth in the garden they were growing in the pot. The only exception would be tomatoes which you can plant deeper than that and the stem below ground will root into the garden soil IF the garden soil is adequately amended. I just replanted a pepper plant for a friend who had planted it too deep. The pepper was just sitting there, the leaves were scorching, until I replanted it to the right depth. Then the new leaves showed no signs of scorch and the plant “took off”. Do not plant peat pots directly into the garden. These peat pots or other pots for transplants that are supposed to degrade in the garden soil often times can create problems and restrict water movement in the area of the pot. Remove as much of it as you can without damaging the roots of the plant. If you do have peat pots or coir pots and planted them with the transplant, tear off any part of the pot sticking above ground so the water in the pot does not “wick up” to the outside air and dry out the root zone. Make sure the soil drains adequately and give it lots of water. Give it some protection from direct winds by putting up a small windbreak for the garden.

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Nematodes Permanent Garden Problem

2 Comments / balls on roots, knots, nematode, root knot, swelling, tomato /

Q. Are these nematodes on my tomato roots in the picture I sent to you? Picture sent from reader A. Yes, you have them. Once you have nematodes they are a permanent pest in your vegetable garden. Your future with them is in managing their new home but you will never be rid of them.             In the past, soil fumigants were available that would dramatically reduce their numbers and easily make them manageable. These soil fumigants are no longer available to homeowners and highly restricted even for commercial applicators due to their potential in damaging the environment. Root knot nematode on tomato             There are multiple approaches in managing nematodes. One way is to exclude them. You can do this by growing vegetables that are highly susceptible in pots or containers. If the pots or containers are in direct contact with the soil containing nematodes, the nematodes will move into the container eventually.             You can impede this by putting down a layer of coarse gravel on top of the soil and putting the containers on top of the gravel.             If you want to grow in the ground with nematodes then heavily enriching the soil with organic material such as high-quality compost will help to deter them. Keeping the soil as healthy as possible is a great deterrent. Nematodes do not seem to like heavily enriched soils.             Another deterrent is to select plants that nematodes do not seem to like very much. There are some vegetables somewhat resistant to nematodes but it is quite lengthy. I will post this list on my blog but a few of them include broccoli, cauliflower, chives, and many mustards.             There are other plants which nematodes really like a lot but plant breeding has produced some varieties which are resistant to nematodes and a few plant diseases. These varieties have capital letters such as V,F,T,N after their names which designate their resistance. The capital N in this case designates nematodes.             Another method is growing marigolds in the vegetable plot. The most effective way is to grow a solid stand of marigolds for at least 2 to 3 months in the planting bed. Turn these marigolds under the soil so that they decompose. Then plant your vegetables.             Some people grow them on the borders of the vegetable plot but it is not as effective as growing a solid stand and turning them under.             There are some products available such as Clandosan which gives some benefit and could also be incorporated into the soil.

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Powdery Mildew on Tomato… what to do?

Leave a Comment / powdery mildew, tomato, vegetable disease, white spots /

Q. I have a problem with my heirloom tomatoes  the leaves on top have mildew on them what is causing this? I have never had this problem before. The plant is producing tomatoes and the leaves on top are still green.  I am baffled! This is not tomato but it gives you an idea what powdery mildew looks like. It looks like someone sprinkled the plants with wheat flour A. I would be very interested if what you are seeing is actually mildew and if you mean the disease powdery mildew. Powdery mildew is a disease that is very specific to certain plants. For instance the powdery mildew on roses cannot attack tomatoes. Powdery mildews can attack numerous plants but each type of powdery mildew is specific to that plant. Powdery mildew is a common disease in desert environments because it can be very active under very low humidities. The environment for this disease to occur is usually the same; somewhat shady areas frequently irrigated with overhead sprinkler type irrigations. This causes water to splash when it hits surfaces. This splashing water can carry the disease from one plant of the same type to a neighboring plant. Nonchemical control of powdery mildew is the same for all types; reduce or eliminate the shade problem and the splashing water problem. Use drip irrigation. Improve air circulation among the plants by not planting too close together and don’t let them shade each other. Give them some space and dont over fertilize them so they get real bushy and have alot of internal shading. Thin out the canopies of the plants to improve air circulation. Go to a different type of growing. Dont let them sprawl but stake them and tie them to stakes to get them more vertical and improve air circulation. Usually if you can do all this you will not need a fungicide. Otherwise there are fungicides you can apply to keep it from spreading.

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