April Garden Calendar

By John Chapman

Weather: April is the transition month from cool to warm weather. We certainly have had a lovely spring with nice rains; we should see a pretty good wild flower show in the desert this year. We may expect some 100+ degree temperatures later in the month.

Diseases and insects: Most aphids and many insects can be controlled with agricultural soap or Orthene. Follow label directions for the mixing of these pesticides.

Those curled, distorted leaves on your citrus and the brown-winkled edges on your rose buds are caused by thrips. They chew on new leaves and petals, and as they develop leaves became wrinkled. Use Orthene or Orthenex for thrips. As fruit ripens, you may observe a brown tracing on the rind. Thrips chew on the outside of fruit. This causes no damage to the leaf's function, nor does this lessen the quality of fruit. Thrips really cause no harm and only cosmetic damage to leaves and fruits. In fact, pollination is a side benefit from thrips. As they scurry about your blooming citrus, they are pollinating flowers.

Homeowners with agaves (century plants) and yucca should keep a wary eye for the snout weevil. These insects will be around the base of your plant; this is also where to apply diasanon granular insecticide. If you have the insects, continue to treat until June first. An indication of their presence is normally upright leaves look wilted. If one plant has snout weevil, all the plants nearby will by ravaged. Prickly pear that looks like it has wet tissue paper hanging on it has cochineal scale. Wash it off with a strong jet of water. The fuzz of the insect makes pesticides ineffective. If you crush the scale between your fingers you will notice that they are bright red. The Native Americans use to use them as a red dye.

Saguaros that have black fluid dripping from them need to be treated quickly or you risk losing them. Cut out black tissue back to green flesh tapering the bottom of the wound downward so water will drain out and let the wound air dry or cover with a Bordeaux paste. Bird holes in saguaros scab naturally, leaving a snug apartment for our feathered friends.

Moths will make their appearance soon. Light puts out an invitation so to speak. Keeping outside lighting to an absolute minimum can help prevent moths from taking up residence.

Flowers: The spring flowers look gorgeous right now and the nurseries are still selling geraniums, petunias, snap dragons and etc, but don't be fooled by this false calendar. The third and fourth week of April is the time to pull up those beautiful cool season flowers and plant with summer flowers so the roots can establish before the heat starts sucking the life out of them. The soil should be kept moist, but not wet. Caution: As many plants die from over watering as from too little water. April is also time to propagate chrysanthemums. Take cuttings from terminal shoots. It is also time to divide chrysanthemums to prevent root binding. Dig up the root clump and remove outside stolons for new plants. The woody center should be discarded.

Vegetables: It is also time to plant cucumber, melons and summer squash. It is getting a bit late for radishes, however, you may wish to gamble and get a crop in before hot weather settles in - you should have them in 60 days. This is a good time to plant onions for green onions or scallions. If you planted short-day onions last fall, they should soon be ready to harvest. Forget carrots and lettuce and the cool season crops, wait for next fall. If you love fresh green beans like I do, plant Blue Lake bush beans or contender. When they start producing I keep the bushes stripped about every eight or nine days and don't let the plants dry out and I had fresh green beans though July before the heat finally took them down.

Trees and shrubs: More trees and shrubs fail because of improper planting than any other single reason. Digging holes too small, setting plants too deep, not keeping the soil moist, and adding amendments to the backfill soil all contribute to plant failure. Always plant so that the top of the root ball is level, or slightly above the surrounding soil. Dig the hole only as deep as the root ball is high. If you dig the hole a little too deep, add some soil to the bottom and compact it until you raise the bottom to the right level. The hole should be dug two to three times as wide as the root ball. This will provide a loosening of the soil and ease the growth of new roots. Do not mix organic amendments into the soil used to backfill the planting hole. Peat, compost, manure or topsoil mixed with, or used, as backfill for the hole will inhibit the development of new roots. Worse yet, the hole filled with improved soil acts as a pot in the ground. As roots grow to the edge of this "in-ground" pot, they stop growing out and begin circling around the inside of the hole. With such a small area to grow roots, trees planted in this fashion often blow over in a strong wind. If they don't blow over, they begin a slow decline as roots grow in on themselves and the trunk. The best soil backfill for the planting hole is that which was dug from the hole. Of course, large rocks should be removed. The soil, and any caliche present should be broken up with a shovel or garden rake to eliminate any large soil clods. The loosened soil can then be filled back in around the roots of the newly planted tree or shrub. With no artificial soil mix present, the roots immediately grow out into the native soil. From there on, they just keep growing, forming an expansive, healthy root system. Putting the mulch on top of the soil will act as a blanket keeping the roots cooler and reducing evaporation. While you're at it, adding a new three to four inch layer of mulch around shrubs and trees will do wonders to preserve moisture and keep the roots cooler. If you have rock mulch, add a new thin layer to dress up the look.

This is a good time to give your palms a haircut. Prune off yellow and brown fronds and the seed spathes at the same time. Trim back old bark to where there is a light tan color. Don't prune fronds more than 180 degrees. We don't want them pruned to look like pineapple. Keep soil moisture up around new and young trees. Always remove the nursery stake. Most trees don't need staking - they will right themselves.

April is an ideal time to plant citrus. Two or three year old nursery trees are a much better buy than older trees. The younger trees establish easier and are a better buy. The trunks of young fruit and citrus should be wrapped to prevent mechanical damage from lawn mowers, weed whips and sunburn as the weather warms up. Citrus are sun-loving plants, but even they appreciate some relief from the sun in the late afternoon. Choose a spot where they appreciate some afternoon shading. Keep new plantings well watered for two weeks and then lengthen your irrigations out gradually until you are watering once a week. In late October you will start lengthening out the time between irrigations. Most of your Navels and Arizona Sweets oranges have been picked by now, but Valencias will still be good right off the tree until early June. Right on the tree is the best place to store them until you are ready to use them. Grapefruit will become sweeter and less acidic until mid June. April and May are the months to enjoy mild delicious grapefruit. Expect a lot of small citrus drop. Citrus thins its fruit naturally and only keeps what the tree can support.

Now is the time to prune out all the dead wood. If you aren't sure if a branch is dead scratch it with your fingernail or knife; if it is green underneath its still alive, if brown it's dead. Winter dormant perennials, and ornamental grasses can be cut back to near the ground. They will re-grow in the spring, producing new shoots from the basal portion of the plant.

Check ties on trees planted last year to make sure they are still stable but loose enough around the trunk to allow for this year's growth. Actually you can and should remove all of trees staked more then a year ago. Mesquite trees weep black sap as they come out of their dormant period. For larger fruits, thin peach and apricot trees to one fruit per one hand width apart. A close examination of fruits may reveal many double and triple Siamese fruit clusters. This is thought to result of last year's high temperatures or this years cold snap during the bloom period. Nectarines usually do poorly in our desert climate and are not recommended.

Lawns: Begin Bermuda grass seeding when nighttime temperatures remain at 65 degrees. Covering with mulch helps keep birds at bay. Bermuda over seeded with rye will resume growth when we have 65 degrees nighttime temperatures. You can encourage the Bermuda to come out of dormancy and gradually kill the rye grass by mowing every four days and lowering the blade each time. Repeat feedings every four weeks throughout the growing season. Sow Bermuda grass at two pounds per 1,000 square feet. Midiron, also known as EZTurf or Bobsod are the two best hybrid choices for the homeowner and can be mowed with a rotary mower. Common or the new improved seeded Bermuda can be grown from seed as soon as nighttime temperatures stay at or above 65 degrees.

Watering: If you're using drip irrigation, this would be a good time to do some deep watering to flush out accumulated salts. To do so later will require much more water. A 24-hour watering will do wonders to rid your soil of salts. As the weather warms up, you'll have to begin increasing the amount of water. Plants will indicate when they need water by having drooping, wilted leaves. Note the time interval; this will tell you just how many days between watering. To measure how much water you are applying to your lawn, set out small pet food or tuna fish cans five feet apart in each direction. When you have watered enough to fill the one with the least amount in it three quarters full, you have put on about free quarters of an inch of water - about right. Note the time it took and set you timer for that amount of time.

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If you have a specific question for John please leave them on his voice mail 480-898-5636 or email him at john@johnchapman.com . Please leave your question, name, city, and phone number. For more of John Chapman’s gardening tips listen to news radio 620am KTAR Saturday morning 7:40-8AM. On Television watch John’s garden segments on Jan D’Atri’s Heart and Home on Sunday 12:30pm and replays Monday evenings 8 pm AZTV broadcast 27, Cable America 4, or Cox 13