April Gardening Calendar
March sometimes leaves us with several late frosts, and those who try to get a jump on the season have to scurry to keep those tender little plants from Jack Frost's icy breath. More than once I've been out there in the middle of the night, setting flats and pots under cover and putting boxes over plants in the ground. But April is a different story, although occasionally a frost does occur, especially at the higher elevations. Warm, sunny days have now arrived. One lovely day follows another, though wind may still be a problem. Flowering cherry, native dogwood, wisteria, rhododendron, azalea, bearded iris, tulips, late daffodils, and even a rose or two, provide spectacular color.
Tender annuals and vegetables can be planted outdoors. Dahlia tubers can go in now, too. This is the month to set out tuberous begonias and tomatoes. Set out rooted cuttings of chrysanthemums and when their new growth is about 4 in. high, pinch out the tips. Be sure to shade all newly set plants from the sun for a few days. Annuals started from seed this month will bloom in July and August.
April is seed-planting time for most vegetables. Sow seeds of greens (chard, lettuce, mustard, spinach) and most root crops (beets, carrots, radishes, turnips). Toward the end of the month sow beans, corn, cucumbers and squash. Leave space for another planting-two to three weeks later-of bush beans and root crops. Set out tomato seedlings. Shop nurseries for herbs, including basil, chives, mint, oregano, parsley and thyme. Plant, plant, and plant some more!
Continue fertilizing, weeding, spraying and baiting. Watering heads the list of chores, for rain showers are few. Plants are growing lustily, and even a short period on the too-dry side will leave its mark for weeks. Since water is the most expensive item of Humboldt gardening, study your watering pattern for a minimum number of hose settings. Look into some of the new watering gadgets which might save time and money.
To save water, smother weeds, and keep the soil cool, spread 1 to 3 inches of bark chips, compost, wood shavings, or other organic material under shrubs and trees, around flowers and vegetables and even in pots. To prevent crown rot, keep the mulch away from trunks and stems.
Spraying for pests is almost as steady a chore as watering. Timing is important if you are to get the full benefit of the spray material. Have a professional attend to large trees since it takes heavy power equipment to penetrate their heavy foliage.
Earwigs and ants can be a severe problem unless you head them off. Aphids can be found on new tip growth on everything from roses and chrysanthemums to camellias. Watch especially tulips, callas and fuchsias. A strong spray from the hose will help, as well as using insecticidal soap. Keep snailing.
Stake tall-growing perennials, such as gladiolus and delphinium, and spray delphinium foliage with Bordeaux solution if you have mildew problems.
As plants finish flowering, many need attention. Cut back trailing kinds such as aubrieta, rock-cress, and basket-of-gold alyssum. On daffodils and other early-flowering bulbs, remove faded flowers but leave the foliage to ripen. On rhododendrons, camellias and lilacs, remove the spent flowers or clusters of flowers. On rhododendrons, be sure you don't damage next year's flower buds growing directly under the flower clusters. Snap off the old flower at the circular scar just above the delicate new buds.
Citrus can be set out in April. Once a plant becomes established, it can tolerate colder weather, but a temporary cover should protect a young citrus the first 2 or 3 winters that it is in the garden-even in the coastal area. Orange trees will grow but our area is too cold for their fruit.
Camellias generally finish flowering this month. Thin out extra dense branch growth. To prevent blight, rake up fallen blossoms, being sure to get every petal. Feed plants with an acid fertilizer and water it in. Keep the soil moist through the coming months, being too dry will cause bud-drop and poor flowering next winter.
Pruning jobs this month include cutting back winter-flowering jasmine. Young abelias and photinias should have their tips removed to prevent straggly growth. On flowering quince and wisteria, wood that has produced flowers should be cut back (next year's flower only come on new growth), and new growth should be shortened several times during the growing season. Prune to shape lilacs (after bloom), and get that overgrown hedge back under control by chopping it way back.
If you are planning color combinations of flowers for future years, here are some suggestions. While the acid-yellow flowers of doronicum and orange tulips is a good combination, do not plant these colors near pink dogwood, pink Clematis montana rubens or red rhododendrons. Avoid yellow basket-of-gold alyssum with pink tulips, and orange and flame azaleas near pink rhododendrons.
If your color taste runs to blue and violet, there is a wealth of those colors this month in wisteria, violas, pansies, forget-me-not, lilacs, ajuga, catmint, aubrietia and bearded irises. There are endless possibilities for using these with pink, red, yellow or orange.
Many different kinds of shrubs (and trees) can be used for hedges, depending on the effect you are after. There are low hedges and tall, evergreen and deciduous, clipped and informally natural. Hedges may be used to guide traffic, to delineate, to screen an undesirable view, or to lessen that nagging afternoon wind that cools our Humboldt gardens.
The main requirements for selecting shrubs are good-looking, dense, healthy foliage and, if they are to be pruned to a certain height or shape, a toleration of continued clipping.
The easiest hedges to maintain are those allowed to keep their normal shape. In other words, you should choose shrubs which, when mature, have the desired height, width, and appearance, with almost no pruning. Of course, they have a rather billowy look instead of being rigidly trim, but in many situations this is preferable, or at least desirably attractive.
Evergreens are excellent for hedging, since they remain beautiful even in winter. Either narrowleaf or broadleaf kinds can be used. Planting time is the same as for shrubs used for other purposes.
When shopping, remember that you do not need the biggest, most shapely, and thus the most expensive specimens. Since hedge plants are grown to become interlocking masses of foliage, you can start with small-size plants. Often in mail-order catalogues, and also in magazine ads, you will find hedge plants marketed in units of 12, 25 or 50. The bigger their root systems, the better; and while husky small plants grow rapidly and vigorously, those slightly larger and bushier with more roots will give quicker results.
The number of plants to buy is figured on the basis of the size the shrubs attain when mature. But since your goal is not specimen bushes but dense, overlapping growth, multiply your count by 2. Plan to space the plants accordingly. Typical hedges, such as privet and barberry, are usually spaced 12 to 18 in. apart.
Before beginning to plant, put stakes at either end of the place where the hedge will be, and run a string between them to indicate the center line. Do not dig individual holes for the bushes unless they are the types that will grow very large and therefore must be widely spaced. For small, bare-root deciduous shrubs, open a long trench with one side directly beneath the string marking the center line. Make the trench wider and deeper than the size of the root systems, and loosen the soil in the bottom. The plants can be lined up single-file against the center-line side, or they can be placed in a staggered arrangement along both sides. They should be set the same depth as in the nursery. If your hedge is to be used as a barrier, consider placing a fence inside it to prevent tunneling.
Whether you should prune at planting time depends upon whether your material is evergreen or deciduous. Evergreens from containers, or balled-and-burlapped, do not need pruning. Spring-set deciduous shrubs do, and fall-planted ones should be pruned early the following spring. This holds true even though the plants are several feet tall, because your goal is dense branching that begins near the ground. To produce such growth you must cut the bushes back to within six inches of the soil line.
Feeding during future years should be done once or twice a year, especially just before the main spring growth. Water whenever rainfall is scant. Remember that these plants are growing in exceptionally crowded conditions and need all the encouragement you can give them.
There are available dozens of shrubs and trees that will make fine hedges. Check with your favorite nursery for appropriate varieties.
"Green Thumb" colloq., traditional, meaning one skilled in gardening, term derived from the result of carrying clay pots. When the soil in clay pots is fertile, algae grows on the interior of the pot's porous surface. Someone who carries many clay pots by hooking their thumbs over the top will have the algae rub off to give them a semi-permanent "green thumb", marking them as a plant expert.
With a handy supply of primary garden aids, you won't be constantly thwarted by commonplace tasks, such as digging a hole or cutting a twig. If you're in doubt as to those tools you would like, try out some of your neighbor's -- temporarily. But don't be a permanent borrower; it's bad for everyone's disposition. Tools can be bought at garden supply, department or hardware stores and at lumber yards.
You'll need as a minimum: