Q. Each year around the end of February until the end of May I experience and irritating problem with springtails. Do you have and suggestions how to eliminate them? I don’t have decaying plants or problem with water in that area. A. Springtails are tiny insects that jump in the air en masse when disturbed, usually at ground level. They love it wet. Springtails are sometimes confused with leafhoppers. But leafhoppers, also very small, reproduce and feed higher on plant leaves of plants like grapes and vegetables. Leafhoppers start appearing about April or May, the time when springtails are disappearing because of the heat and dryness. Both jump about the same distances when disturbed but look totally different with a hand lens or microscope.             I can see you know this insect because springtails are found commonly in wet soils with rotting or decaying plants or infesting open bodies of water like summing pools and puddles. That would’ve been my first comment to you if you hadn’t made that last statement. Sometimes springtails become a nuisance inside the house in wet areas with light like bathrooms. Outside, I commonly see them in cooler, dark areas of lawns that are kept too wet during the cooler months. Springtails like stagnant, wet areas and are attracted to light. I’ve seen them as nuisance problems in swimming pools or spas. Leafhoppers, on the other hand, like it hot and dry.             The bottom line in all habitats suitable for springtails is water or wetness. If it’s dry, they will disappear. They must feed and so rotting or decaying plants is important nearby, but water and wetness is more important. So, in our climate oftentimes they are found in irrigated shady spots.             I know what you told me, but the key to managing or eliminating these guys is drying up wet areas. This might be as simple as improving air circulation in that area. Wetness is oftentimes accentuated in darker areas without much air movement or north sides of buildings.             Pesticides do not work in the long haul. It’s really getting the area to dry up will or at least should clean up the problem. Ways to dry it out are to get more air movement in that area and/or more light. The rooting plants (organic matter they use for feed) will eventually disappear with time. Be careful of excessive irrigation nearby. Do not water daily. Water and then let the surface area dry out. Use deeper rooted plants in the area if plants are there. Bigger, deep rooted plants can handle longer periods of time without water applied. If mulch is present, let it dry out before irrigating again or remove it. If rock is used, smaller rock like ¼ inch minus might allow you to keep the area drier and longer times between irrigations. If it is unbearable then try spraying the area starting in late January with one of the horticultural oils. Spray the surface of the soil in hopes of suffocating them. I would like you to read the information at this link http://ipm.ucanr.edu/PMG/PESTNOTES/pn74136.html

Q. We’re considering planting a fig tree grove in our school garden this year. How long typically does it take for them to produce figs ready for harvest? 12 year old fig tree kept small by pruning A. Figs produce fruit very quickly after planting. You should start seeing fruit produced the year after planting in most varieties. Remember, figs produce fruit on the wood that grew last year as well as the wood actively growing.             Figs can be very big trees if you allow them to grow. They can also be cut back to a much smaller size. You mentioned planting a grove of figs. Their planting distances apart should be the same as their maximum height. If you plant them 10 feet apart, don’t let them grow above 10 feet tall. Figs with early Briba crop and later main crop growing together             Remember that figs do great and desert climates, in desert soils, in the desert heat with low humidity. But they are heavy water users much like palm trees. Water them the same as you would any other fruit tree and don’t expect production if you don’t give them enough water. They will benefit from soil covered with woodchips simply because the woodchips keep the soil moist longer.

Q. I have a Museum Palo Verde and a crepe myrtle planted in the Fall of 2012. The  Palo Verde has grown well but the crepe myrtle hasn’t grown much in seven years. The roots of the Palo Verde are now lifting the stone ring I built around it. Can those big roots be cut out? A. Palo Verde  I will tell you about cutting the roots at the end but let’s talk about your situation first. You have two different types of trees; the Palo Verde is native to the desert Southwest and considered xeric (desert adapted) while the crepe myrtle is native to the wetter and richer soils of South and Southeast Asia. It is considered mesic and not desert adapted. You can’t grow them the same way, under the same conditions, and have good results.             The Palo Verde can handle the poor growing conditions of our desert while the crepe myrtle must be pampered. Your crepe myrtle isn’t getting pampered that’s why you have problems with it. These two trees are planted, managed and irrigated differently.             The Palo Verde will grow roots where water is applied to desert soils. If you water Palo Verde 2 to 3 feet deep and let the upper foot of soil dry between irrigations, the roots will  grow mostly 2 to 3 feet deep and not bother that stone ring lying on the surface of the soil. You can  control its rate of growth by giving it lots of water occasionally and let the soil dry out before the next irrigation. Every time it gets a deep drink of water, it will grow. When the soil is dry, it does not.             The Palo Verde is more forgiving of desert soil even when it’s planted badly. I’m not saying it was or wasn’t planted correctly, but it tolerates bad soils better if they are amended before planting. The Palo Verde will look better if it’s planted in decent soil at the beginning, but how and where you apply water will dictate how fast it grows and where its roots are located.             You can’t do any of those things with crepe myrtle. Crepe myrtle will not tolerate soils if amended badly at planting time. It won’t like the hotter and harsher locations in the landscape. But Palo Verde will. Crepe myrtle will grow much better if the soil is continuously moist and covered with 3 to 4 inches of woodchips. Palo Verde will like this too, but it can sail through desert hotspots and poorly amended soils better than crepe myrtle.             If they are both on the same irrigation valve, then you will have a problem because the Palo Verde will get water when you think the crepe myrtle needs it. They should be watered separately. That would be too often for Palo Verde. It will grow shallow roots because its watered too often. If these trees are on separate irrigation valves, then the Palo Verde can be watered less often than the crepe myrtle. Using separate valves benefits both of them.             Can you cut off the roots of the Palo Verde that are causing problems? You can remove a few of them each year for the next three years but start watering the Palo Verde less often and give it more water with each of its applications. Get its roots deeper and out of the way. Apply water to at least half the area under the canopies of these trees. Crepe Myrtle Readers crepe myrtle On your crepe myrtle, I would put a ½ to one inch layer of compost 12 inches away from the trunk to about three foot away. You can get it bagged from Viragrow. I think you will need about ten bags or less. Concentrate the compost closest to irrigation water or drip emitters where it will get wet and decompose faster and move the leachate into the ground toward the roots. The tree will respond faster if you can auger as many holes as possible around the trunk to about 12 inches deep and fill them with compost. Spreading it on the top of the soil will work but it will take longer for the tree to get the benefits. Cover that compost area with woodchips about three to four inches deep. You can get them free from the University Orchard in NLV (N. Decatur and Horse Drive) or their office complex on the corner of Paradise Rd and Windmill just south of the airport. Call their Master Gardener helpline at 702-257-5555 and make sure they have the woodchips available before you go. Then I would prune back the height of your crepe myrtle and try to force some new growth lower on the trunk. Prune the top back as much as possible while still keeping the growth on top. I am hoping you will see some new growth lower on the trunk in the spring. This growth will help strengthen the trunk and I am hoping you will not need to stake it in a couple of years.

Q. My roses are not doing good because there is no sun by the wall where they are planted. Can you please suggest other flowers that can be planted there? From the look of the leaves in this picture you might need to amend the soil before planting roses. Roses appreciate amended soil in the soil surface covered in wood chips, not rock. A. Whenever you have a location in a landscape that’s not getting much sun, you can’t grow flowering plants in that location. They need more sun  to produce flowers. Instead, focus on plants that do not produce flowers but are still ornamental. In other words, forget most flowering plants in that location. Flowering plants will need at least six to eight hours of sunlight to flower well.             Some examples of ornamental, nonflowering plants for nondesert shady areas might include Agapanthus, Box Leaf Euonymus, Dwarf Indian Hawthorne, asparagus fern, Mondo grass, sago palm, Algerian ivy, purple flax, split leaf philodendron, dwarf Burford Holly, heavenly bamboo, and Oregon grape. All of these require compost mixed into the soil at the time of planting, moist soil and they will do better with woodchip mulch on the soil surface. All of these plants are mesic (nondesert) so make sure the soil is amended with compost at the time of planting.

Q. I am relatively new to this desert environment and I know hardly anything about desert plants.  Would you recommend the best book(s) you have read that describe these desert plants? Which are best as decorative lawn plants? When to plant them and how to care for them? A. I would focus on something written for the Las Vegas climate or secondly Tucson, Arizona and lastly the desert Southwest. Books I suggest are available on Amazon and Abe’s Books as well as other places if you search using the author names.             Linn Mills from Las Vegas and Dick Post from Reno teamed up and wrote a book called the Nevada Gardeners Guide that has information split between both northern Nevada and southern Nevada. Its focus was to understand both Mojave Desert (Las Vegas) and Great Basin (Reno) conditions, soils and how to manage a landscape growing in them.              Tucson has a similar climate to Las Vegas; a bit warmer and humid in the winter and wetter during the summer months. From here is Plants for Dry Climates by Mary Rose Duffield and Warren Jones. It includes desert landscape design ideas as well. The newest edition includes and expanded section plant selection and care.             Adjust books not written for the Las Vegas by recognizing that our winter low temperatures can get into the low twenties and even the upper teens on occasion. Trees you select for the “backbone” of your desert landscape should withstand these temperatures or you are asking for trouble. Play around with lesser important landscape plants that don’t tolerate these temperatures but don’t expect them to survive forever.             A solid reference book is the Sunset Western Garden Book. It is not specific for the Las Vegas area but does a good job discussing desert soils, desert environments as well as an exhaustive list of plants suitable for advanced gardeners.             I use Chris Martin’s Virtual Library of Phoenix Landscape Plants, free online and housed at Arizona State University, quite a bit. Just realize plants discussed are used in the Phoenix climate and soils. Adjust your selection for our colder winter temperatures and not as much heat in the summer.             Several knowledgeable local experts like the Southern Nevada Water Authority (SNWA) searchable database of landscape plants for Las Vegas, called “Find Plants”.  It is a good online reference when first looking for possible plants to use.

Q. Some time ago you mentioned a plant used between stones or pavers, and when you step on it, it releases a fragrance. Can you tell me the name of that plant again? I would sure appreciate it. A. I don’t remember a specific ornamental groundcover that I mentioned but creeping thyme will work, and it does come in culinary and nonculinary types. You can direct seed it in those cracks by preparing the soil with compost, watering the soil to settle it, lightly cover the seed with sand and keeping the soil moist until you see it germinating.             You can use creeping thyme for cooking in a pinch but use new growth. Don’t plant it in extremely hot locations but it will work in an open area without reflected heat from a south or west facing wall. Plant it just like you would in a vegetable garden.

Q. I recently purchased some Green Cloud Texas Rangers from a building supply store and was wondering if it is safe to plant them now since our weather is turning colder. A, Since you emailed this question to me it froze in parts of the valley this past week. But not to worry. This kind of weather can be freakish this time of year. It normally does not freeze until the second week of December. But the ground is still warm. After you plant you want the roots to grow but you should not care about the top growing yet. The best planting time for woody plants is from late September until mid-November. You can still plant at other times but its just not as good because of root growth.             The ground is still warm enough to plant. The magic number for landscape plant root growth is about 50F. Of course, roots of plants grow faster in warmer soils, but they will still grow at 50F. The ground never froze or was even close to freezing. The soil temperature rises up and down mimicking the air temperature, but these temperature swings are much smaller compared to air temperatures. For instance, in some areas vegetables like tomatoes, peppers and squash froze, but the ground never did. The soil in the ground was much warmer than the air.             If you want the soil to warm up fast then keep it dark, fluffy, dry and in the sun. Those kinds of soils have wide temperature swings from very warm to very cold but still not as cold as the air. Landscape plant roots like to grow in those warm temperatures during the day. Soils that are not fluffy, wet and instead are covered by a surface mulch or in the shade stay cooler and don’t swing up and down as much.             Surface mulch keeps soils warmer in the Fall and cooler in the Spring.

Q. I have a ten-year-old Bartlett pear tree and the pears are kind of small, about 3 inches long. The label says they ripen in August but mine are not ripe until end of October. November. I pick them, leave them out in kitchen and they become juicy and ripe. I water the trees heavily once a week and the fruit improve. Is there any way to make tree produce larger fruit? A. Bartlett pear has the potential here for getting the same size as in the stores with the same or better quality. It is a matter of how many fruit there are compared to the number of leaves. If there are a lot of fruit and not enough leaves to support the fruit, the fruit will be smaller.              For Bartlett pear you should have about 45 to 50 leaves for each piece of fruit so that they can get larger. The fruit is produced on spurs that form an average of five fruit per cluster. Remove all but one fruit per cluster when the fruit has recently set and is still very small. This may be hard to judge when the fruit is just starting out in the spring but try removing all but one of the fruit in each cluster. If you want the fruit larger, next year remove more. Do it when they are small. Don’t wait. The remaining fruit will get larger. This is called “thinning the crop” or just plain “thinning”.             Fruit also needs water present to expand and get big when its growing. Make sure the tree gets adequate water while the fruit is enlarging. If the tree doesn’t, the fruit will not grow as much. I don’t know if your watering is often enough or not. But in midsummer I would guess the trees should be watered deeply two or three times a week. Once a week is good in the Fall when it cools off.             Pick Bartlett pears when they are still green, but the green has changed from dark green to light green. Your label is wrong. Harvesting should be in about late September or early October, not August. If you aren’t sure, pick one and cut it open to look at the seeds. The seeds should be all brown then go ahead and pick them. Picking may last two weeks as they don’t all get ready to pick at once.             Pick the fruit before they turn yellow because this keeps the fruit texture buttery instead of gritty. Then let them ripen in a cool place out of the sun until they are ready to eat in a few days. When you get them from the store they are sometimes green. Ripen them like that before eating them.

Q. I have two desert ironwood trees that are ten years old, 12 to 16 feet tall, in my landscape. A nursery told me I should water these trees deep daily for 7 to 10 days. I did that and after the third day the leaves turned a pale yellow and fell off to the touch, so I have stopped watering. The soil moisture meter I use is showing 7 to 8. Any thoughts because I really don’t want to hurt these beautiful trees. A. When you call these trees “desert ironwood” I am guessing you mean the ironwood native to the Sonoran Desert. It’s a beautiful native desert tree that does not need to be watered very often. It is considered an indicator tree for growing citrus so during cold weather in southern Nevada it might get damaged. There are other trees called ironwood as well.             Because it grows in the desert, it is not used to getting water very often. When you water this tree, irrigate the area under its canopy to a depth in the soil about 18 to 24 inches. Then don’t water again until the soil dries out. Because it’s a desert tree, it will not like wet soil but soil that occasionally gets wet. That’s why the leaves are yellowing and falling off; watering is too often and the roots are suffocating.             On the soil moisture sensor, or meter that you have, the needle should be in the three or four spot before you water again. The meter reads zero to ten with ten being sopping wet. You want the soil to be on the dry side about six inches deep, not the wet side when you water it again.             When you do water, try a hose, an inexpensive sprinkler that screws onto the end of the hose and a mechanical timer that shuts off the water. If you are like me, I forget to turn it off. The mechanical timer will shut it off for me. Set it for one hour. Take a length of rebar and stick it into the ground in three places and make sure the water got to the right depth. If the water isn’t deep enough then water for 15 minutes more.

Q.  I am looking for plants that bloom all season long like lantana. Can you help me? A. I would rather that you use a searchable plant database online like the one created by Southern Nevada Water Authority. It’s a good one. Google or use your favorite internet browser and type in “find plants SNWA”. The Sunset Zone for Las Vegas is Zone 11. The rest of the information needed for the database should be straight forward. Use this before you go to the nursery and get a list of plants that you want.             If you want plants selection advice from me, ask for five suggestions at your nursery and then I can help you pick which might be best. There is a lot of information available to help you decide. Select trees and shrubs that you cannot afford to lose using a minimum winter temperature of 20F. If we have a few warm winters in a row then you won’t lose anything!             If you select plants that tolerate winter temperatures above this temperature then expect to lose them occasionally during cold winters. Even at 20F we will have 30 to 50-year freezes that will get as low as 12F. If the 20F plants are established in the landscape well before that, they will probably survive.