Q. Will either dwarf lime or lemon trees do well here? We consider pots but our patio faces the west and gets very hot. We have a small space for pots in the front yard which faces east. Any suggestions?   A. The principle limitation for citrus here is winter cold. Cold tolerance in citrus generally follows this progression of tolerance from the most hardy to least goes something like this: (most) kumquat, Meyer’s lemon, grapefruit, Mandarin or Satsuma orange, navel orange and lime (least). Eureka lemon tree in Las Vegas. Fruit still immature.             Once you get to navel orange the rest will not handle any freezing. You should locate citrus in the part of the yard that is the warmest in the winter and protected from cold winter winds.             If you like lemons, Meyer’s is a good choice and very popular in Las Vegas even though it is not a true lemon. I would put limes only in much protected locations.

Q. How often should I water my California pepper tree, Mediteranean fan palm and my Canary Island date palm These are the only trees I have on my property. I hand water them. How often should I be watering them with the extreme temps we are having? A. We have to take into consideration both how often and how much to water. The “how often” will be the same. Or in other words all the trees you mentioned will all be watered with about the same frequency.             How much is also going to be about the same except for their size. The larger the canopy, or size of the tree, the more water it uses. This time of year, with temperatures in the triple digits, I would be watering two to three times a week depending on your soil and if you have mulch on the soil surface. Generally speaking, a layer of mulch will save you about one extra day that you do not have to water.             Make sure, though, that you are leaving at least one day dry between irrigations. Watering too often and keeping the soil sopping wet will lead to roots rotting. If soil is piled against the trunk and kept wet, the trunk will rot.             I would suggest that you put a “moat”, depression or basin around the trees to contain the irrigation water from your hose. This depression, if it is maintained so that it stays at the same capacity around the tree, will guarantee that the trees get the right amount of water each time. Irrigation basin for watering with surface mulch applied             The depression can be a moat that is a wide donut or trench around the plants. This can be a small one when first planted but must be increased in capacity as the plant gets bigger. The depression or donut should be 3 to 4 inches deep and wide enough to contain 5 to 10 gallons of water when young and expanded to contain up to 40 gallons when thre tree is larger in a few years.             The only exception to this is the palm. Many palms have the same size canopy when they are five feet tall as when they are 20 feet tall. With the same sized canopy later in life, they will use the same or similar amount of water. So for these types of palms, one sized depression should be fine during its lifetime.             There have been criticisms with this type of watering that letting water surround the trunk might cause the trunk to “rot” or become diseased. Watering with a moat or donut around the tree is far more likely to cause problems if wet soil is left in contact with the trunk. Water against the trunks of trees when irrigating does not kill the tree UNLESS you do it too frequently and keep the trunk wet. In many cases it is worse to have wet soil against the trunk.             For this reason I prefer a depression around the tree rather than a “moat” or “donut” around it. As long as the trunk dries for 24 hourse after an irrigation, trunk or collar rot will not be a problem. It WILL be a problem, however, if wet soil is left in contact with the trunk. So don’t pile soil against the trunk that will get and stay wet between irrigations.             These depressions should be gentle, sloping depressions and not deep trenches from World War I!. When constructing these depressions, I like to start on the “high side” of the tree and use a common hoe to construct it. Pull soil to the low side when you create the depression so you can “berm” up on the low side and contain the water. The bottom of the depression should be as flat as possible.             Start creating your depression and run your hose with a gentle amount of water coming out. Craft your depression or moat so that the water begins to fill this moat as you are constructing it. Running the water will help you get the bottom of the moat level and fill the basin around the tree without moving the hose.             Buy one of those inexpensive hose water timers that you turn on like a kitchen timer. It will turn off the water depending on the number of minutes you dial in. It will save you water in the long run because, if you are like me, we tend to forget what’s cooking if we don’t use a timer.             Don’t just dig a trench and fill it with water when you are done. It will never be level unless you dig it at the same time you are running the water. This type of irrigation is called “basin irrigation”, a type of flood irrigation but you are using a hose. Fill this basin twice when you water. The basin can also be used for applying fertilizer.

Q. I have been having problems with my shrubs and plants growing this year and am hoping you can help. I started planting in April, I planted mostly evergreen shrubs because I like to look at the green all year around. I used top soil to plant them, and they have all died. Is there something I am doing wrong? Can you tell me what evergreens I should plant(ones that stay green all year around), what month I should plant them and exactly how I should plant them? What soil to use? And how often I should water them? I don’t have a watering system so I water them myself. I aprreciate it so much and am hopeful you can help me. Thank you.     A. You have asked for a whole book worth of information. It is not something that I could do or explain to you easily. Any planting you want to do now that is summer should be delayed until the end of September to the middle of October, no later. Dig and prepare your holes BEFORE you buy your plants. Start with trees first. This is a “window shopping” trip. Don’t buy them yet. You will leave with something, but not the trees. When you leave the nursery you should be leaving with the plant, the phosphorus fertilizer, a bag of soil amendment for each plant. Stake the trees. If the tree is really small and you plant it correctly, you may not need to stake it. Shop for trees that will shade the south and west side of your home for some break from the summer heat. For these two spots I would pick trees that don’t get more than 20 to 30 feet tall for a one story house and they should drop their leaves in the fall. Leaf drop in the late fall will allow some winter sun in that can warm the house and reduce you heating costs. Do not plant these trees any closer to the house or themselves than half of their mature height. Once you have found the trees you want, then go home and dig the holes and take all the soil prepartion stuff with you. All these plants will need to have soil improvement before you plant them. This means you will have to dig each hole about five times wider than the container it comes in. It should be the depth of the container, not much deeper. Next, remove rocks larger than a golf ball from the soil taken from the hole. When this is done you will mix a “planter mix” soil amendment with the soil removed from the hole. I would also add a phosphorus fertilizer to this soil as well, something like 0-46-0 or similar. About two handfuls of this for each hole will be enough for shrubs and small trees. This is all mixed together and put back into the hole and soak it with water as deep as you can. The next weekend buy your plants and plant them in this improved soil. Plant them in this hole the same depth as they were in the container. Add water to the hole as you are putting the soil back in around the roots. Make a tall ring around the plant about two feet from the trunk and six inches tall. This will be the basin or container you will use for adding water with your hose. This is important to do. Water twice a week for three weeks. Each time you water, fill the basin twice. Water once a week the same way after this. Most of the plants you are looking for are sold locally. If you go to a nursery and ask someone for help and explain to them what you are looking for, they will direct you to “foolproof” evergreen plants for your home. There are plants that will be fairly easy to grow and then there are plants that are difficult to grow. They can help guide you. Always buy the smallest plant that is in good health you can get. Why pay the grower more money when you can grow it larger yourself? Also, if you have been losing plants then you will not want to invest a lot until you get this growing thing down pat.  

Several have asked about grafted vegetables and what is the advantage. Grafting vegetables has been around for a number of years now and has had some success in greenhouse production primarily. It started in Asia and has spread to Europe, primarily where heavy cropping (high yields) and disease problems can build rapidly. So here are some Q and A’s I grabbed from some sites to further explain it. It is not hard to do, easier than woody plants. The method I am most familiar with is using plastic tubing to hold the top and rootstock together until they grow together. Other methods are done as well. For backyard gardeners it is mostly just for fun right now but you can buy grafted transplants for the home market. In vegetable production in greenhouses, most of the damage from continuous cropping is caused by soil-borne diseases and nematodes. As a countermeasure to the damage caused by soil-bone diseases such as Fusarium wilt, bacterial wilt and nematodes, grafting of fruit-bearing vegetables is popular in Japan. Plants are grafted onto various rootstock species and varieties, by a range of grafting methods. Recently, the tube grafting method has been developed for plugs. This is popular in the manual grafting of tomato, eggplant and cucumber plants. Grafting robots and healing chambers have been developed, and are used in nurseries producing grafted plugs. Since grafting gives increased disease tolerance and vigor to crops, it will be useful in the low-input sustainable horticulture of the future. Application of Grafting to Vegetable Production The production of grafted plants first began in Japan and Korea in the late 1920s with watermelon grafted onto gourd rootstock. Eggplant was grafted onto scarlet eggplant in the 1950s. Since then, the area of fruit-bearing vegetables based on grafted plants has increased. The proportion of the area in Japan producing grafted watermelon, cucumber, melon, tomato and eggplant reached 57% of the total production area in 1980, and 59% in 1990 Objectives of Vegetable Grafting The main objective of grafting is to avoid soil-borne diseases such as Fusarium wilt in Cucurbitaceae (Cucumber, melon etc.) and bacterial wilt in Solanaceae (tomato, pepper etc.). Species and Varieties for Grafting Inter-generic grafting is used in the production of many fruit-bearing vegetables, i.e. cucumber grafted on pumpkin, watermelon, on bottle gourd, melon on white gourd (also known as wax gourd). Inter-specific grafting (grafting on to a different species) is generally applied to eggplant. Scarlet eggplant and S. torvum Swartz are popular rootstock for eggplant production. A large number of varieties for rootstock have been bred and released for use by growers in Japan. Grafting Methods for Different Types of Fruit-Bearing Vegetable Tomato plants are mainly grafted by conventional cleft grafting. Tube grafting has recently been developed for vegetable seedlings grown by plug culture. Cleft Grafting The stem of the scion (at the fair-leaf stage), and the rootstock (at the four to five-leaf stage) are cut at right angles, each with 2-3 leaves remaining on the stem. The stem of the scion is cut in a wedge, and the tapered end fitted into a cleft cut in the end of the rootstock. The graft is then held firm with a plastic clip. Tube Grafting Tube grafting makes it possible to graft small plants grown in plug trays two or three times faster than the conventional method. The smaller the plants, the more plants can be fitted into healing chambers or acclimation rooms. For this reason, tube grafting is popular among Japanese seedling producers. The optimum growth stage for grafting varies according to the kind of plug tray used. Plants in small cells must be grafted at an earlier growth stage, and require tubes with a smaller inside diameter. First, the rootstock is cut at a slant. The scion is cut in the same way. Elastic tubes with a side-slit are placed onto the cut end of the rootstock. The cut ends of the scions are then inserted into the tube, splicing the cut surfaces of the scions and rootstock together. Eggplant Eggplant is grafted mainly by cleft or tube grafting. The growth rate differs according to the species of rootstock used. The number of days from sowing to grafting varies accordingly. Cucumber Tongue Approach Grafting Slant-cut grafting is easy to do, and has recently become popular. This grafting method was developed for robotic grafting. It is important to remove the 1st leaf and lateral buds when a cotyledon of rootstock is cut on a slant. Planting Watermelon Cut grafting is popular for watermelon. A schematic diagram of cut grafting is shown. Melon Melon plants are mainly grafted by tongue approach grafting. Tongue approach grafting for melon is similar to that used for cucumber plants. Healing and Acclimatization Grafting should be carried out in a shady place sheltered from the wind, to avoid wilting of the grafted plants. Grafted plants are usually healed and acclimated in a plastic tunnel. The healing and acclimatization are very important for grafted plants to survive. The tunnel is covered with materials which provide shade and maintain inside humidity: silver/white cheese-cloth (outside) and transparent film (inside). During acclimatization, it is recommended to keep light levels at about 3 to 5 klx. Before grafting: Expose the scion and rootstock to sunshine for two to three days; Withhold water from the plants to avoid spindly growth, and Make sure that the scions and rootstock have stems of a similar diameter. After grafting, keeping the grafted plants at about 30°C and with more than 95% relative humidity for three days of healing promotes the survival ratio. Gradually, the relative humidity is then lowered and the light intensity increased. During healing and acclimatization, it is important to keep a constant air temperature in the tunnel, in order to maintain high humidity. If wilting is observed, foliar spraying of grafted plants with water is effective in helping them survive. The shading materials and films should be adjusted according to the daily weather, with more shade on a fine day. Healing has

From A Reader: Bob, This is mostly a thank you for your answer above and hopefully providing some info for any other of your readers. If you remember my question previously….   Tomatoes are All Vines and Few Fruits … Q. With five tomato plants all I really get is beautiful, huge green vine, why don’t I get tomatoes? Being from East … I moved our little garden from the west side of the big fig tree to the east side hoping to get more sun on the tomato plants.  I can report some success with  this move.  I actually put in three plants, a Big Boy variety (still have hopes) in one of those upside-down hanging planters just outside the little garden on the west side of it.  Then a Better Boy variety on the west end of our raised planter and a Celebrity variety on the east end.  Both of these are caged and are now about 5-6 foot high.  We have been eating very nice tomatoes since the first of June.  The plants seemed to take a breather for about a week of the very hot weather but today (6 July) we took off another tomato and there are 14-16 green ones which we hope will turn. The Big Boy did not do too well, although it may again be a sunlight problem.  It only gave us three tomatoes and they were not very big, about 1/1/2 to 2″.  I actually hung the bag from a branch of the fig tree with a pole support under.  I had to constantly trim back the fig tree, and even then it only got sunlight till about 12 noon.  Fairly close and next to it is the Better Boy.  Got several tomatoes but not very big, about 2 1/2″ +/-, and enough sunlight might be a problem here too.  The best performer was/is the Celebrity.  Got at least a dozen so far and they are 3-3 1/2″.  I do think it gets more sunlight and this is the reason it has performed better.  I tried to treat all the same with the fertilizer and watering.

Q. When I spoke to the master gardener volunteers last year about watering peaches (I had a Stark bare root from Gurney’s that only made it until August) I received a wide range of answers including 35 gallons per week. Any recommended rule of thumb for watering these? A. There are two things we have to consider when watering; how much and when. A third thing to consider is where and should be considered as the tree gets older. The how often part doesnt change as the trees get bigger. The “how much” does since “big trees use more water than little trees.” The  “where” to put the water is important. As tree roots have to spread wider to anchor the tree against wind and carrying its fruit load and get enough water to support its size we have to encourage growth away from the trunk as well. How Much. Regarding watering, give them the same amount of water as the container you would find them growing in, in the nursery. If it is equivalent to five gallon container, give them 5 gallons, 15 gallon container then 15 gallons. Even though these containers are not actually five or fifteen gallon capacity it still gives you about the right idea. Of course you can give them more than that but that would be the minimum and gauged according to size, increasing yearly until their mature size. Fully mature trees might require 30 to 40 gallons each time you water. If  possible, try to change the number, size and spacing of emitters instead of the number of minutes on the irrigation clock.   Example: Newly Planted 5 gal Fruit Trees (Number of Minutes Kept the Same)  1st to 2nd Year – 4 to 6 gallons (ex. 2 each 3gph emitters, one on each side) 2nd to 3rd Year – 8 to 10 gallons (ex. 3 each 3gph emitters, triangular spacing) 3rd to 5th Year – 10 to 15 gallons (ex. 4 each 3 gph emitters, square spacing) 4t Year and Up – Replace emitters with more gph and/or more emitters Where. Wet to an area equal to the canopy when young. As it matures the wetted pattern should be at least half the area under the canopy if possible. In commercial orchards of smaller trees like peaches and almonds under drip irrigation this “wetted area” is genearly considered in two stages. The first stage is when they are young and a drip line is laid near the trunks with two emitters; one on each side of the trunk about 18 inches from it. The second stage as the tree approaches production, in the third and fourth years, a second drip line can be added on the opposite side of the trunk and the two lines places about 18 inches from the trunk on either side. Two more emitters are added to this new line so that the emitters are in a “square” pattern surrounding the trunk. This wets a larger area under the area under the canopy. When. You should never have to water daily even in the hottest time of the year. The most frequent in our hot dry desert climate will most likely be every three days in peak summer water use. If you do, you run the risk of root rot or collar (lower trunk) rot. The dormant winter frequency may be 10 days to 2 weeks apart if you have mulch. Water to a depth of 18 – 24 inches each time you water. When to Water February 1 – April 30   Water once a week May 1    Water twice a week (or sooner, depends on weather) June, July, August Water three times a week if excessively hot, sandy soils and no surface mulch September 1    Water twice a week October 15   Water once a week December 15 (leaf drop) Water every ten days to two weeks through the winter