Xtremehorticulture

Xtremehorticulture of the Desert

What to Use on Vegetable Seedlings Decimated by Insects

Leave a Comment / Bt, cutworms, Dipel, milky spore, spring insect control, Thuricide, vegetable garden /

Q. The day after I planted seedlings in my 4×8 raised bed I noticed they were decimated by some kind of insect. When I was amending the soil I noticed some small worm-like critters in the soil. I sprayed Bt but it evidently didn’t do anything to help the situation. I was told to use a powder called “milky spore disease” to kill any grubs or grub-like insects in the soil. Have you ever heard of this product? They said it works and I only have to apply it one time. Can you advise me on this product and where I might find it or some other solution?  Decimated pepper   A. The milky spore product only works on Japanese beetle and a few closely related insects which we do not have in southern Nevada. It is a bacterium and works rather slowly, if it will work at all, on pests we have in southern Nevada.             Bt works differently. It works on those insects that mature or pupate into either moths or butterflies. So if the immature insect turns into a beetle for instance it will not work. So without knowing which insect is doing damage it is hard to know what will work. Cutworm larva               The other alternative is to use a conventional pesticide approved for use on vegetables and has insect grubs or larvae on the label. These insecticides leave a poisonous residue for longer-lasting insect control.             This time of year Bt is a good product to use because it will control many of the insects causing damage right now. Look for products with a label that says Dipel or Thuricide. Forget the milky spore bacterium control in your case.             I am sending you a picture of what the cutworm larva looks like and its adult form, a moth. I will also post it on my blog. Bt can be sprayed on the soil and left undisturbed (no hoeing or irrigating after the application) for a few days but you have to repeat your applications to get any long term control. Corn earworm moth adult http://ipm.illinois.edu/ifvn/volume15/frveg1506.html             This is the time of year that moths are flying, mating, laying eggs and larvae are out looking for food. Usual cutworm damage is at the soil surface, not on the leaves.

What to Use on Vegetable Seedlings Decimated by Insects Read More »

Planting Two Cherries in a Single Hole to Save Space and Pollination

4 Comments / multiple trees in a single hole, pollination, small yard, sweet cherries /

Q. I have two cherry trees and one needs to pollinate the other. Can I plant both trees in the same hole so save space?  The trees grow to 20 feet and I will keep them pruned to a smaller size. Sweet cherries produced at the Orchard. Production is erratic in the Las Vegas Valley.   A. Yes, you can. Plant them about 18 inches apart, one on the east side and one on the west side of the hole. Try to pick varieties that are similar in vigor (how strong they grow) and on the same variety of rootstock. Multiple apple trees planted in a single hole at Dave Wilson Nursery             I will warn you that sweet cherries are squirrely in our hot desert environment. They produce cherries in some microenvironments and not in others. They usually seem to do better in backyards that are somewhat protected (no strong winds) and have a more humid environment during pollination.             If you plant these two trees together, keep them occupying only half of the canopy. Do not let them compete with each other but keep them occupy their own, separate spaces. This means there will be a clear physical separation between the plants in their own half circle of canopy space. Also, do not let one get bigger than the other. Keep them pruned to a similar size.             These cherries must also bloom at the same time if they are to pollinate one another. Check your pollination charts to make sure they are compatible.

Planting Two Cherries in a Single Hole to Save Space and Pollination Read More »

Some Fertilizers Will Cause Staining

Leave a Comment / cement, concrete, fertilizer stain, fruit, iron stain /

Q. I have a question regarding fertilizing.  My husband used a fertilizer that stained our pavers and the bottom of our pool in spots. Do you know of a solution to remove those stains? A. The fertilizer most likely had iron sulfate in it. The spots would be dark reddish brown or brown. Muriatic acid would remove it. Be careful using it. Iron spray staining grape berries. Be careful spraying iron on fruit vines and trees that have fruit on them if you care about appearances.             If it is in the bottom of the pool and water is in the pool there is not much you can do about that unless the pool was empty. The bag should have warned you, hopefully, to use a drop spreader if it was for a lawn.

Some Fertilizers Will Cause Staining Read More »

Plants Need to be Placed in Outside Environments with Care

Leave a Comment / acclimatization, plant acclimation, reduce transplant shock, time of year for planting, transplanting /

Q. Last Christmas a friend bought for me a tiny pine tree about 6″ tall. It is now 2′ tall and I need to transplant it. When is the best time of year to do this?   A. It is April and getting too late now. I would wait and plant it some time between mid-September and mid-October as temperatures are cooling. However, if you run the risk of losing it, plant it now.             You don’t mention how you were growing it. If you were growing it inside, not outside, you will need to gradually bring it into the outside environment or it could go into shock. This is called plant acclimatization and requires about three weeks inside a garage or outside shade shelter and then planting it.

Plants Need to be Placed in Outside Environments with Care Read More »

Black Spots on Watermelon Leaves Could Be Several Different Insects

Leave a Comment / aphids, black specks, disease, insect, melons, squash bug, whiteflies, whitefly, Yellow sticky traps /

Q. I have attempted to grow watermelons for the first time last summer and everything was looking good until it got hot. These tiny black specks appeared on the back of some of the leaves.  I was told it was aphids but they weren’t sure.  I hope you can see them clearly from the picture I’ve attached. Should I use insecticidal soap as recommended or something else?  A. I tried to magnify the picture so I could see the black spots better. I was curious if these were in fact from insects or not. I could not see it clearly but whatever it was, it appeared that it was no longer a problem and the leaves seemed nice and healthy.             Aphids are cool weather insects and so when the heat hit they should have disappeared. The big insect problems for you on watermelon would be aphids earlier in the season during cool weather, squash bugs shortly after planting and whiteflies (during the heat).             Yellow sticky traps can provide a method to determine if whiteflies are a problem or not. I will post a short video on my blog on how to make these rather than buy them. They are handy to place in the garden for insect monitoring.             Soap and water sprays are good but must be done about every three or four days and the underside of the leaves must be sprayed as well. Squash bugs are nasty and can be vacuumed or hand-picked or delay planting by seed until after June 1. If you are hand picking or vacuuming squash bugs then be diligent for about three or four weeks and keeping the plants cleaned off every couple of days by hand until mid-June to avoid most of the problems with this insect.       Thanks to Garry Pearson, Lead Greenhouse Managerat UC Davis CAES,                 Department of Vegetable Crops, during his presentations on greenhouses in Afghanistan.

Black Spots on Watermelon Leaves Could Be Several Different Insects Read More »

Rolly pollies, Pillbugs, Sowbugs Potential Big Problem with Strawberries

Leave a Comment / control pillbugs sowbugs rolly pollies on strawberries, what's eating my strawberries /

Q. We are growing the most beautiful strawberries, the problem is that the rollie pollies are eating them before we get a chance to pick them. We have applied dicotomes earth but it has barely slowed them down. What else can we try. A. I feel your pain. This is a tough problem. The roly pollies, sometimes we call them pillbugs or sowbugs, can be a very common pest of soft fruits and vegetables. These crustaceans (they are not insects but are more closely classified closer to lobsters) usually feed and abound in rotting or decaying plant matter which we usually call organic matter. Stuff from plants which collects on the surface of the soil where it is wet will begin to decay. Technical information on sowbugs in the Southwest This decaying organic matter is a usual source of food for these common pests. They can be good guys since they feed on decaying plant matter and convert it to something that can be recycled and benefit the plants. Once they get established they can get a little overzealous and start to consume other plants or plant parts which are soft and succulent. If strawberries come in contact with the soil surface where these creatures are feeding they don’t distinguish between soft decaying organic matter or soft succulent strawberries. So the control measures usually focus on keeping the strawberries from touching surface of the soil or decaying plant matter and picking when they are ripe and not letting them get soft. This would require that the fruit be kept elevated off of the soil surface. I wish that I had a good answer for you on how to do this. I don’t. Other people may recommend using diatomaceous earth but I am not convinced that this will work with your roly pollies. It is better suited for very soft bodied pests which crawl along the surface of the soil. These very sharp diatoms, at least this is the thought process, cuts or lacerates the pest and they succumb to the lacerations. You can also use traps in the beds and remove them from the traps as they accumulate. This does not exterminate them but it does help to reduce their numbers and hopefully the damage from their numbers. These traps can be something that lies on top of the soil surface such as strips of carpet, cardboard or wood. Removing these pests from these traps is simple. Since they like their social gatherings in darkness they tend to gather in these shady spots. Remove the shade and remove them by hand. You can also put out semi rotten tomatoes or other vegetables which will act like magnets and attract these varmints.  Then you can scoop up these rotting fruits and vegetables along with the pillbugs and dispose of them.  That won’t get rid of them but it will take the numbers down.  Sluggo Plus contains iron phosphide and spinosad and is labeled for sowbugs, pillbugs, and cutworms and is registered as an organic pest control product for gardens and available at Home Depot. The original sluggo is for controlling slugs and snails.

Rolly pollies, Pillbugs, Sowbugs Potential Big Problem with Strawberries Read More »

Harvest Garlic Different Timing in Desert Environment

Leave a Comment / when to harvest garlic, when to harvest green onions, when to harvest onions /

Q. When do I know to harvest garlic, Walla Walla sweet onions, green onions and garlic?   A. Garlic should be harvested in our hot, dry climate when the tops have browned down by about 1/3. In other locations where it is not so hot they usually will harvest when the ½ of the tops have turned brown or when they fall over. We cannot wait that long in the hot desert. A common mistake is to wait too long to harvest garlic in the desert. This is elephant garlic in the foreground, not one of my favorites (but it is big and impresses nongardeners), but this is close to ready for harvesting. You can note the change in color of the foliage and dieback. Garlic that was in front of it was already harvested as it was an earlier garlic variety. The irrigation is drip tape with emitters spaced every four inches with the tape spaced one foot apart.             There is a thin, tight “wrapping” around the cloves when you harvest garlic correctly. For appearance purposes and storage it is important that this wrap be continuous and tight around the cloves. If you wait too long before the final harvest, this covering starts to rot away, leaving the cloves exposed.             Sweet onions like Walla Walla are harvested when the tops have fallen over. Do not step on the necks to ready them for harvesting unless you plan to eat them fresh and not planning them for storage. This is Contessa sweet onion. The top of the plant in the center has fallen over signalling the bulb is ready to harvest. The others are close but not ready yet. When the bulb is ready for harvest the neck will collapse near the bulb and the weight from the top will cause it to fall. This closes off the bulb and will not allow diseases to enter the interior of the bulb and helps for long term storage. The other thing to do for storage is cure the harvested bulbs. Leave the collapsed tops on the plants and put them off the ground and in the shade to cure for a few days. After the tops dry down, cut them off leaving an inch of the dried top remaining.             The drying down of the tops and tops falling over is a natural “sealing” process of the bulb. Stepping on the tops can allow disease organisms to enter the bulb because the neck has not dried down properly and may prevent any storage of the bulb.             Scallions are really nothing more than green or immature onions that have not yet begun to bulb, just barely started bulbing or cannot bulb. In the case of the Welsh onion, which is traditionally grown as a scallion, it cannot bulb up. White Lisbon onion is also grown as a scallion but this onion will bulb up if left in the ground too long. Harvest it before it starts to bulb.  

Harvest Garlic Different Timing in Desert Environment Read More »

Should I Add Vinegar or Citric Acid to My Water?

Leave a Comment / benefits of adding vinegar to water, increasing acidity, lowering alkalinity, lowering pH, pH of water /

Q. Have you ever heard of adding vinegar or citric acid when fertilizing indoor plants in our area? We collect the rain water and use it for our indoor plants.  Diagrammatic representation of pH scale as found at https://en.wikipedia.org/wiki/PH Numbers are logarithmic so each unit change represents a factor of 10 (e.g. 6 to 7 = 10; 6 to 8 = 100; 6 to 9 = 1000) similar to the same scale used for measuring earthquake intensity.  A. Quite a few people do this to lower our water’s alkalinity but the effect is short-lived. Our tap water carries a lot of calcium and magnesium salts. The acids are neutralized by these and other salts. You could determine how much acid to add fairly simply by using some pH litmus paper, like they use for swimming pools. You would add small amounts of acid until you see a shift in the pH of your water into the acid range. The perfect pH is 6.8 which is the pH of the plant sap of many plants. Let this water/acid mixture sit for 30 minutes or so and check it again. Keep adding small amounts until you see the pH stay steady in that 6.8 pH range then you can use it for watering. As long as you stay with the same water source, you would add the same amount of acid each time to arrive at basically the same pH. If you change water sources, then you would have to do it all over again. However, as soon as you pour this mixture on our soils it will shoot back up again to the alkaline range because of the massive amounts of alkaline types of minerals that reside in our soils. In short, I wouldn’t waste my time doing this unless it helps you sleep better at night. Just adding a big scoop of good compost to your water instead of vinegar will probably do more good. Let the compost steep for a few hours through a porous sock like old pantyhose. Use it immediately for watering. Put the spent compost around some outdoor plants or in your garden. Good compost is likely to still have gnats so don’t apply the spent compost to the soils of indoor plants.

Should I Add Vinegar or Citric Acid to My Water? Read More »

Eliminating Lawn Can Lead to Problems for Established Trees

Leave a Comment / convert from lawn to desert landscaping, desert landscape, desert landscaping, drought, retrofitting landscape, xeriscape /

Q. I have a beautiful Loquat tree where the leaves have suddenly started to turn yellow and fell off.   Most of the fruit has also fallen off. The tree was located in the middle of grass. I had the landscape converted to desert rock in September. At the same time watering schedule was changed. I suspect it is being under watered. But before I increase it I want to ask if the cold winter we had here could have caused this yellowing. A. Thanks for the pictures. It is probably not the cold. In a lawn situation the roots go everywhere and anywhere and usually spread to about 1½ to 2 times its height away from the trunk. Loquat with rock mulch applied after growing in a lawn for a few years. In many cases the drip emitters do not apply the water in the same places as lawn irrigation and the plant roots of established trees and shrubs die back. This results in leaf drop and eventual die back of the limbs of established trees and shrubs.             In drip irrigation we usually place the emitters a foot or so from the trunk. This bypasses about 80% of the root system it created when growing under a lawn.             So, yes, it probably is drought but perhaps not because you are not delivering enough water. It is more likely that most of the tree roots are not receiving water. You can place emitters over a greater area under the canopy of the tree. But I would also reduce the size of the root system.             Try root pruning the tree to reduce the size of the root system so it is closer to the emitters. Keep tree roots contained in the area directly under the canopy. Wet the soil thoroughly under the canopy and vertically slice the roots in a circle all around the tree at the edge of the canopy. This can be done with a sharpened spade. Leaf drop of established loquat due to replacement of lawn with rock mulch and drip irrigation.             At the same time, thin the canopy by removing wood. This reduces the tree’s demand for water. A tree that size will probably require 20 to 30 gallons each time you water. With the lawn now gone, the tree will actually use more water since the cooling capacity of the lawn has been removed.

Eliminating Lawn Can Lead to Problems for Established Trees Read More »

How to Keep Harvested Garlic a Long Time

Leave a Comment / drying garlic, postharvest, storage /

Q. I know garlic will keep 4 to 6 months in cooler climates. Since I don’t have a root cellar, what are my options for storing garlic? Tom at the Orchard tying garlic in onion netting for storage and sale. You can use pantyhose and cut the bulbs loose from the netting when one is needed. A. After harvesting garlic from the field or garden, we will tie the garlic together in bunches and let them hang outside to dry in the shade for a week or two. This helps “cure” the garlic bulb and readies it for storage. Some people want fresh garlic and in this case it is not “cured” but should be consumed soon.             Ideal storage environment is cool and dry, away from other food items that might absorb the flavor of garlic. Garlic under home conditions will store for about 2 to 3 months in a kitchen environment. Garlic hanging under shade cloth, tied in bunches, for curing for a couple of weeks.             An option is to dry the garlic and it will store indefinitely. If you still have garlic left after two to three months of storage, you can peel it, slice it thin by hand or in a food processor, dry it outside in the shade and low humidity of our Las Vegas environment. Always dry food in the shade, not in direct sunlight here. Keep drying temperatures below 140F if using a commercial drier or oven.

How to Keep Harvested Garlic a Long Time Read More »