Xtremehorticulture

Can I Use Burlap as a Shadecloth?

Q. Can I use burlap for shade cloth? Burlap fabric  A. Don’t use burlap as a solid piece in place of shade cloth for permanent shade. It is fine for creating permanent shade for people or pets but not for plants. Be careful how much heat it traps under it if it is located too close to humans and other animals. Plants are green and need sunlight for photosynthesis. Usually about 60 to 70% sunlight. People and pets don’t need as much. Use Shade Cloth Instead It comes in different percentages of shade ranging from about 30% to 100%. Shade cloth for plants ranges from 20 to about 50% shade. Plants that flower and produce fruits like tomatoes, peppers, and eggplant need more light than leafy plants: 20 to 40% shade. Shade more than this interferes with flowering and fruiting. t This is 30% shade cloth used on a tunnel for growing sun sensitive vegetables and herbs in the desert sun in Las Vegas Plants that only grow leaves and no flowers such as lettuce, spinach, Swiss chard, greens can handle shade up to about 50%. After 50% shade, they grow poorly. Too dark. Not enough light. Most burlap I have seen produces much more shade than this and would not be a good choice when growing plants.  You can make 50% shade out of wooden 1×2’s by omitting every other piece of wood. These are called “lathe houses”. Similarly, 30-40% shade can be done the same way but by eliminating 2 and leaving every 3rd 1×2.

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Starting a Fall Vegetable Garden

Q. Could you help me get a fall garden going? Please send me a list of crops that grow in Las Vegas. I live in the northwest area off of Ann Road and Jones in Las Vegas A. I posted a calendar for planting in the fall on my blog. Download a copy there but I will give you a rundown of the crops which are normally started this time of year in the eastern Mojave Desert.             First, some background. There are two planting times each year. Plant cool season vegetables and herbs that withstand frost and cold during the late summer, fall, winter and spring months. Plant the warm season, winter-tender vegetables and herbs when danger of frost has passed and into the mid-summer months. Warm season crops die or perform poorly during cold or freezing weather.             Even though it’s still hot now, this is the time of year to plant several fall and winter crops. Notice that I said many, not all. Exact planting dates vary with soil and air temperatures, the time plants require before they are ready to harvest as well as the quality of the end product.             Cool season crops that require 60 or more days before harvesting will be just fine if planted now. It is too early to plant crops like radishes which are ready to harvest in 30 days.                         Exact planting dates vary with your garden microclimate. Gardens located in warm microclimates have different planting dates from those gardens in cooler microclimates. If you are lucky enough to have a landscape with more than one microclimate, you can stagger your planting dates so that the same crops mature a few days or even a week or two apart.             Plant gardens that face West or South later in the fall but earlier in the spring. Gardens facing east or north are planted in the reverse order.             The following vegetables can be planted during September from seed or seed pieces for fall, winter and spring harvest: beets, broccoli, carrots, collards, endive, Irish potatoes, kale, kohlrabi, lettuce, peas, rutabagas, spinach and Swiss chard.             The following could be planted as small transplants: broccoli, Brussels sprouts, cauliflower, cabbage, celery and Chinese cabbage. If temperatures are unusually hot, delay putting in transplants until weather cools off a bit.             Mulch the soil to keep the seeds and roots of transplants moist and cool.

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Vegetable and Herb Planting Calendar Re-Posted as PDF

I made some changes in the one I posted earlier and embedded it from Scribd as a pdf document. Please let me know if you have trouble downloading it by posting here on the blog. This has been put together for elevations of about 500 ft (160m) to 3000 ft (1000m) elevations at 36 degrees N. Latitude in a desert environment. Vegetable and Herb Planting Calendar

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Horseradish is Best Harvested in Cool Months

Q. I really enjoy the blog. Had a question for you.I planted some horseradish about a month ago. It’s growing nicely (I think — first time I’ve planted it). But I have five-six nice big leaves coming off the plant.I was wondering when I can tell it’s ready for harvest. I’ve looked online, but most of the instructions involve spring planting and a fall harvest. Since I planted in fall, per the extension service instructions, is there a way to know when they’re ready to harvest? A. Horseradish does quite nicely here for a northern climate perennial but it needs time to develop its roots where we derive the spicy condiment. After the leaves have fully established, it will take two or three months, at a minimum, for harvestable roots (rhizomes). It is in the mustard family where many members have spicy leaves and stems used in salads. This is perennial mustard so it sprouts from its underground rhizomes each year. The rhizome can be dug in the fall or spring, divided and replanted again to create new plants.  In colder parts of the United States most planting is done in the spring. But here in the semi-south (actually we are in a ‘Transition Zone’ climatically between north and south), we can plant a lot of things in the fall that are recommended for spring planting in the north. You could plant during our entire winter if you are careful and have a warm microclimate, or create one, in your garden. Our real “winter” here is the summer months which are more brutal to plants than our winter.   If your plant got two or three months of good growth before fall I would’ve told you to harvest it, divide the rhizome and let it heal and then replant. Now that we are in the second week of November I think it is a little dangerous to recommend that unless you have that warm microclimate I was talking about.  I would wait until February to mid-March to dig it, divide the rhizome if it needs dividing, let it heal for 48 hours and replant it. If the rhizome has not given you enough growth for it to be divided, then I would just replant it.  Horseradish is a tough plant. In some parts of the country it is so tough it can be invasive in the garden. Any little section of the rhizome left in the ground after digging can create new plants. So you do not need a big part of that rhizome to start a new one. There are some critical gardening tips that you need to follow when planting or replanting horseradish or any plant started from rhizomes. Make sure the knife you use when dividing the rhizome is clean and sanitized. The cuttings you prepare for replanting can be anywhere from 3 to 6 inches in length. Plant the rhizomes horizontally about 2 inches deep and about a foot apart. Don’t plant until all fresh cuts, or any damage to the rhizome, has had time to heal.  Heal the rhizomes by placing them in a warm spot (warm compared to outside, 60F or so) for 48 hours. This will allow any cuts or damage to begin to suberize or begin the healing process.  Be careful not to re-damage the rhizomes when planting. Those parts of the rhizome that recently healed can be damaged easily.  Make sure the soil has been prepared with good quality compost to a depth of 18 inches. Horseradish likes composted manure and prefers to be kept moist but not overly wet. It can survive droughty conditions but is not productive. It likes surface mulches 2 to 3 inches deep that keeps the soil moist and cool. You should dig them during the cool fall or spring months for harvesting and replanting for best flavor. Use the large central root for cooking and the smaller, side roots for planting. Horseradish root will go bad very quickly after you start shredding or grating it for cooking. The root oxidizes quickly which ruins the flavor. Use it as soon as possible after harvest. Shredded or grated horseradish root can be stored in vinegar for short periods of time as this will help keep it from oxidizing. If you are storing it in the refrigerator, keep the roots moist and in long pieces until you need it. It will probably store in the refrigerator for about 3 to 4 weeks in more humid areas such as the crisper. It can store longer than this but you would need more sophisticated storage than just a refrigerator.

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Growing Saffron in the Desert

Q. I live in Summerlin and I want to grow saffron crocus. Is our area suitable for the successful propagation of this plant? If so, can you tell me the best source for the sativus corms? I would like to plant in the early spring if possible. Saffron crocus growing at the orchard A. Yes, saffron will grow here and does quite well. Saffron, a type of crocus is in the iris family, is one of the most expensive spices in the world. It takes about 60,000 crocus flowers to make one pound of saffron. One of our volunteers began growing it successfully at the orchard a couple of years ago.             There is no seed so propagation is by planting the bulb which is actually a corm much like a tulip bulb. Your best source for corms for planting will be online. Saffron crocus loves our alkaline desert soils, hot dry climate and mild winters. It does well in climates and soils that can grow pistachios.             The bulbs of saffron should be planted in full sun in heavily composted desert soil with additions of your favorite phosphorus fertilizer. Planting should be about 4 inches deep and about 4 inches apart. They should be irrigated and mulched with light mulch such as straw. Lightly fertilize continuously through the season to increase bulb size so it can be further propagated.             There are different levels of quality in saffron usually based on its color and taste. You can affect the quality of saffron by manipulating how it is grown. Grow it so it is “happy” and it will produce a good quality product. Saffron production manual

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Harvesting Herbs and Easily Damaged Vegetables

Nothing is worse than harvesting herbs and eggplant and by the time you get them in the door they are withered or soft and no longer firm. Or your products didn’t last very long in the cooler. Here are some suggestions on how to harvest these tender plants from the garden and keep them fresh. The ideal time to harvest most herbs is as early in the morning as possible. This is the time of day when temperatures are lowest, humidity is highest and winds are low. This is also the time for herbs when those volatile oils that are so important are at their peak and flavors are best. Harvesting should be at a time when the flower buds are just starting to form but before they open. When the flowering cycle begins, the plant begins to shove nutrients at the flowers and subsequent seeds which takes precedence over the production of leaves and stems. Flower formation indicates this loss of nutrients in leaves and stems is about to happen. After some familiarity you will begin to visually predict when this occurs as you note changes in the growth of the plant. If at all possible, spray herbs and soft vegetables with a mist of water 10 to 20 minutes before harvesting to wash dirt from the surface, cool the plant down and rehydrate the surface. In the case of vegetables, the larger the vegetables the longer it takes to cool the plant down. So don’t expect that a quick rinse of eggplant for instance to have much impact in cooling the fruit down internally. In our dry climate the cooling effect from spraying a plant down with water may last ten minutes at best and then the temperature begins to climb back toward the air temperature quickly. On the contrary, a light mist of water on the surface of most delicate herbs and leafy vegetables will cool the plants down considerably. Make sure you take a clean bucket with cool, clean water (non chlorinated would be best) into the field with you. During summer months the water temperature should be at least cool to the touch and cooler than the air temperature. For those requiring more exacting guidelines you should have temperatures about 55 to 65 F. There are some plants that can be packed in ice while others cannot. Icing is usually reserved for cold hardier plants like broccoli, spinach, cilantro, parsley, green onions, and Brussels sprouts. Icing more tender plants will result in injury. The four major enemies to plant quality and storage life occur after harvest: damage from handling, low humidity and water loss, high temperatures, and direct sunlight. Do everything you can to keep these enemies from damaging your harvest. Damage from handling. Harvesting requires a sharp and sterile knife or shears. Herbs and soft vegetables should be severed from the plant cleanly without tearing or ripping and lifted rather than pulled and immediately immersed in clean, cool water. Any surface tearing or scarring impacts the quality of herbs and soft vegetables and their storage life. If you have long fingernails or wear jewelry on your hands that could tear or rip, wear thin plastic gloves to protect these tender plant parts from damage. This may sound like these precautions are “overboard” but if you expect to store these plant parts for any length of time, damage to the surface of the plant allows water to be lost and disease pathogens entrance. All herbs and soft vegetables have to be inspected for damage and sorted for quality. Sorting or grading of products, if not done carefully and out of harsh conditions, can intensify damage and result in even more losses. Low humidity and water loss. Our desert climate is naturally low in humidity. That is great for growing plants but not so after harvesting. As soon as the herbs or vegetables are severed from the plant its source of water is removed, air enters the stems, water no longer moves through the severed plant part. Plants with roots attached can lose water from leaf and stem surfaces and water from the roots replenishes lost water. This keeps the leaves and stems hydrated and cool. Evaporation of water from leaves and stems helps cool the plant. As water is lost from severed plant parts their freshness and quality is compromised. Immersing them in cool, clean water immediately after harvest helps keep these products hydrated and fresh. Keep these plant parts out of the wind, direct sunlight and high temperatures which drive excessive water loss. High temperatures. It should go without much explanation that harvested plant parts should be kept cool unless you are dealing with vegetables that require high temperature and humidity after harvest such as sweet potatoes.Direct sunlight. The energy from the sun can be deceivingly destructive. I don’t know how many times I have told people in the field to put harvested products in the shade, even if it is under the shade of other plants. This is one of the most commonly abused practices after harvest. I observed small-scale producers in Kenya on the slopes of Mt. Kenya harvesting products and putting them in direct sunlight to be picked up by the co-op truck a few hours later. To top it all, these products were sorted and graded at the co-op headquarters by co-op members in DIRECT SUNLIGHT! Coop members then did not understand why half or more of their harvest was rejected by the exporter. Cleaning. A light salt solution (two tbs per five gallons or 35 g. per 20 L) can clean products of insects without damaging plant parts. Straight table salt, sodium chloride, has two chemicals that can cause plant damage; sodium and chloride ions. If too intense, damage will result. A better salt might be a potassium based salt rather than sodium which can be very toxic to plants. Immerse the plant parts in salt water, remove and dry in a salad spinner and place in a

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