APRIL  IN YOUR GARDEN

Annuals:

  • (See also Sweet Peas and Wildflowers)
  • Some of your cool-season annuals may still be going strong, especially along the immediate coast.  If so, leave them in.  Otherwise, it’s time to replant these with warm-season varieties.
  • Warm-season annuals should be in abundant supply and in all sizes right now.  Choices include petunias, lobelia, verbena, marigold, ageratum, cosmos, impatiens, coleus, torenia and begonias.
  • If you are in a warm inland garden this is the first good month for planting the real hot weather sizzlers like dahlias, zinnias, gomphrena, cleome, portulaca and lisianthus.
  • Because of their quick growth and heavy flowering potential, annuals need more fertilizing than most other plants in the garden.
  • Keep deadheading (removing spent flowers) from annuals to help them continue blooming abundantly.

Avocados:

  • Apply your second feeding to avocado trees this month.  A mature avocado tree should be given between ½ and 1 pound of actual nitrogen per inch of trunk diameter.  (Example: 15-30 pounds of 20% nitrogen if a six-inch trunk; 30-60 pounds of 10% nitrogen if a six-inch trunk, etc.)
  • Avocados are putting on quite a bit of new growth and the plants should look about their healthiest of the year.
  • Be sure to keep a very thick blanket of mulch, compost or fallen leaves under mature avocadoes at all times.
  • This is a very good month for planting avocados.  Avocados prefer to be planted at the beginning of the warm half of the year.

Azaleas:

 

  • Many azaleas are blooming now.  For these blooming plants be cautious of getting the flowers wet from overhead watering or a late season rain.  The flowers will turn to mush with water on them, especially pure white hybrids.
  • Azaleas are nearly dormant while they bloom, so this is an excellent time to plant.
  • They don’t really require pruning, but if you do need to shape them or reduce their size a bit as soon as they finish blooming is the best time to do it.

Bearded Iris:

  • Most bearded iris are now developing flower buds or are even blooming.
  • Apply another application of a good well-balanced, general-purpose organic fertilizer this month and the flower production will be even better.  Any fertilizer labeled for roses (by not with insecticides) will do.
  • Trim off faded flower stalks just above the foliage when the last flower fades.

Bulbs, rhizomes, tubers, etc:

  •  (See also Bearded Iris and Tuberous Begonias)
  • Bulbs that are in bloom in most parts of Orange County now include most alliums (late in the month), anemone, babiana, bletilla (just starting), calla, chasmanthe (finishing up), crocosmia (formerly called montbretia), daffodils, Dutch Iris, freesia, hippeastrum, hyacinth, iphieon (finishing up), ixia, narcissus, nectaroscordum, ornithogalum, ranunculus, scilla campanulata, sparaxis, sprekelia, tritonia, tulips and watsonia (just starting.
  • If you didn’t last month, plant or re-plant dahlia tubers now.
  • This is the first opportunity to plant caladium.  These should be planted when the soil is warm, so wait at another month for them.
  • As spring bulbs finish blooming do not hurry to cut back the foliage or ignore the plant.  Keep the leaves in place and continue watering until the leaves naturally turn brown and dry, then you can cut them off.  The green leaves are sending energy to the bulb for next season.  Of course, for one-year bulbs like most anemone, crocus, hyacinth, muscari, ranunculus and tulips, after they are done blooming, pull them and toss them.  These will not return reliably next year.

California Native Plants:

  • Some of these will still be blooming and growing well, but many other will already be slowing down and preparing for the long, hot and dry summer months.
  • Be very cautious irrigating most of our native plants during the summer.  Most of these are adapted to a winter wet – summer dry moisture cycle.  Too frequent irrigations now (especially in soils with a clay content) will cause problems.

Camellias:

  • Some Japanese Camellias may still be in full bloom.  Be sure to keep the old flowers picked up underneath the plant to eliminate the occurrence of a disease called Camellia Petal Blight (a fungal disease that causes the petals to turn brown and mushy).
  • After your camellia finishes blooming is the time to do any shaping or pruning.
  • Apply the first of three feedings to your camellia about 4-6 weeks after it finishes blooming.  Use an “azalea/camellia” or acid based fertilizer, like cottonseed meal.  Apply a light application (camellias are not heavy feeders) evenly around the base of the plant, but do not dig it into the soil.  Camellias (and many other plants) have very delicate surface roots within the top inch of soil that are easily damaged by cultivation.  You will feed again 4-6 weeks later and then you final feeding 4-6 weeks later again.

Citrus:

  • Citrus are growing pretty well this month and many varieties will still be flowering.
  • For plants in the ground, continue fertilizing this month and every month from now until July.  Use a fertilizer rich in such trace minerals as iron, zinc, manganese, copper and others.  These ingredients are usually well represented in organic fertilizers like Dr. Earth.
  • Honeybees are the primary pollinators for citrus.  Be sure to encourage these very beneficial insects and avoid any pesticides that might harm them.
  • Continue periodically checking for ants.  Control them from climbing up the trunk of the tree or onto the branches.  Ants “farm” such pests as scale, whitefly and mealybug, which are common on citrus.

Clematis:

  • Clematis are continuing to grow quickly now.  Keep feeding them with a balanced organic fertilizer to keep them going.
  • Most varieties will be blooming and those that are not should be heavily budded.
  • Help them by guiding their fragile stems or carefully tying them as they grow.

Deciduous Fruit Trees:

 

  • Apply the second and final fertilizing this month.  Apple, apricot, peach, plum, etc. should be given between about ½ pound of actual nitrogen per inch of trunk diameter.  (Example: 15 pounds of 20% nitrogen if a six-inch trunk; 30 pounds of 10% nitrogen if a six-inch trunk, etc.)
  • Do the first thinning this month, the earlier the better.  Twist off the excess fruit, leaving one per cluster and about one every six inches or so.

Fuchsias:

  • You should have stopped pinching at the end of last month.  Now you want your plants to grow out and begin flowering.  If you pinched and fertilized regularly over the past couple of months your plants will be very full and set loads of flowers.
  • Now that you are getting your plants ready to flower it is time to switch fertilizers.  Put away the high nitrogen fertilizer you have been using and now use a one that is more balanced or even slightly higher in phosphorus, to promote blooms.
  • Keep the plants well watered, especially during warm spells.
  • Watch for Fuchsia Gall Mites, which are a serious pest of these plants.  Look for any signs of puckered or distorted new growth.  If you discover any, pinch it out and dispose of it immediately.  A pesticide treatment is usually required.

Gardenias:

  • Gardenias are growing well now and may even be showing some blooms.
  • If you didn’t apply fertilizer last month be sure to this month.  Use a fertilizer with lots of trace minerals, such as most organic types and alternate with an acidic formula to keep the pH down.
  • This is a great month to apply an iron supplement to your plants.  Iron only works well in warm soil temperature, so applying it now will have a significant benefit.

Groundcovers:

  • This and last month are the best time to plant slopes, especially large scale plantings.  Erosion will be minimized since most of the rains are behind us.
  • California native groundcover plants are probably still blooming well now.  However, this is not a good month to plant natives.  Wait until late this fall.
  • In general, groundcover planting is easy to accomplish now.  Mulch between the plants to reduce weed growth, improve soil quality and reduce irrigations.
  • This is the best time of the year to perform a heavy cut-back of warm-season varieties.  Many groundcovers build up considerable thatch and loose their vigor if not cut back periodically.  Fertilize immediately after, to insure quick recovery.
  • Check irrigation systems on slopes.  Adjust heads, check clogged lines and add to the system as necessary, before the warm summer weather.

Herbs:

  • Now that the weather is warm and the days are growing longer it is finally time to plant basil.  Choose a sunny location.
  • Many perennial herbs can be planted nearly year-round, but are particularly well suited to spring planting, since they thrive during the warm summer months.  These include marjoram, oregano, rosemary, sage, thyme, catmint, catnip, chamomile, comfrey, feverfew, lavender, lemon balm, lemon grass, lemon verbena, St. johns wort, tansy, tarragon and thyme.
  • Especially in warm inland gardens, this is the last chance to plant a quick crop of fast growing, cool-season herbs like anise, arugula, borage, chervil, cilantro, dill and fennel.
  • Still a good time to rejuvenate certain old or tired herbs by giving them a hard trim.  Many herbs can be scalped almost to the soil line and, with fertilizing, will recover quickly.  Other herbs like catmint, catnip, feverfew, lemon verbena, rosemary, rue, sage and tansy should be cut a bit higher.  Cut lavender only very lightly.

Hydrangeas:

  • These are continuing to wake up from the cool months and should be putting on new growth; a few may even be beginning to bloom.
  • Apply a moderate feeding.
  • Do not prune hydrangeas at all this time of the year.
  • If you want to try to get blue or lavender flowers on your otherwise pink plant continue applying Aluminum Sulfate to the soil.

Lawns:

  • This is a good month to plant new cool-season lawns from seed or sod (fescue, ryegrass, bluegrass).
  • This is the first reliable month to plant warm-season lawns (hybrid bermudagrass, St. Augustine, etc.). Most warm-season grasses do not grow from seed and are installed as sod.
  • Feed all lawns this month.  Cool-season grasses like fescue, ryegrass and bluegrass are still at their peak.  Warm-season grasses like bermudagrass, St. Augustine and zoysia are also growing well again.  Feeding these warm-season grasses now will help them return to their deep green color.
  • Remember, cool-season lawns should be mowed about a half an inch lower in the cool months than in the warm months.  Keep the mower at this lower height for another month or so.

Perennials:

  • (See also Bearded Iris, Bulbs/Rhizomes/Tubers, Fuchsias and Tuberous Begonias)
  • There is a myriad of new and interesting plants at nurseries this month.  A slow walk through the nursery now will stimulate lots of exciting plant possibilities.
  • Most of your perennial “chores” should have already been done and you can now enjoy your perennials in all their colorful glory.
  • This is a good planting month for perennials.
  • Keep fertilizing perennials.  The frequency and amount will depend upon the formulation that you are using.
  • Sub-tropical perennial are beginning to perk up now.  These include begonias, heliotrope, impatiens, lamium, pentas (starflower) and plectranthus.
  • By now most of the perennials that completely withdrew to below ground for the cool winter months have sprouting from the soil again.  Some to be on the lookout for include caladium, calla (colored types), chocolate cosmos and true lilies.
  • Tall, upright, spiking perennials like dahlia (perennial types), delphinium, foxglove (digitalis), kniphofia (red hot poker), liatris, lilies (lilium), monkshood (aconitum), oriental poppy and thalictrum (meadow rue) should be staked to support the flower stalks and prevent breaking.  Tie the stalks to the stakes as they grow.
  • Removing the myriad of spent or old flowers regularly to produce more new flowers.  This is a good time to cut some fresh flowers for a vase as well.

Records, Catalogs, Books and Organizations:

  • Be sure to keep making lots of entries in your garden journal now about what is blooming, what you like and what you don’t.  Entries that you will make now will guide you and remind you of what you should do this fall and next spring.
  • Be sure to make notes in your journal about the names and varieties of what you planted.  Often, much later, the name or variety of a plant cannot be remembered.
  • This is the most popular month for home garden tours.  If you haven’t participated in one of these you have missed one of the best gardening experiences.

Roses:

  • Roses are making their first big bloom this month.  This “first bloom” is the most spectacular of the entire year.  The flowers will be huge and the color rich.  The flowers will hold well in the cooler temperatures of April and the foliage should be lush and healthy as well.  Enjoy the show.
  • Continue fertilizing roses.  They are heavy feeders.  Do not use soil-applied fertilizers that are combined with a systemic insecticide.  These products are very disruptive to soil life (beneficial microorganisms, bacteria, mycorrhizal fungi, earthworms, etc.).  Many rosarians also believe they reduce the vigor of the rose.
  • Granular, well-balanced, organic fertilizers work especially well for roses and most of these will encourage beneficial soil life.
  • Begin deadheading roses as they fade.  The rule of thumb is to prune to just above a leaf with five leaflets.  Floribunda’s, many English roses and some others are deadheaded on very short stems until the last of the flowers in the cluster have faded.  Then cut down to just above the first leaf with five leaflets.
  • Be on the lookout for pests.  Aphids can usually be hosed off with a strong jet of water.  Flower thrips may require an insecticide.
  • Keep on the lookout for diseases.  Powdery mildew and rust are the primary concerns.  Regular grooming, early removal of infested leaves, good air circulation and full sun will help considerably.
  • If diseases do require a fungicide, use one of the newer, safer, organic products available.  These include Rose Defense (a neem oil extract), E-Rase (jojoba oil) or Saf-T-Cide (straight paraffinic oil).
  • Potted roses are in good supply and the selection is excellent now at the nursery.  It is a good time to add more or upgrade any that you are struggling with.
  • For the biggest flowers pinch out some of the competing buds while they are very small.

Shrubs & Vines:

  • (See also the information under Azaleas, Camellias, Gardenias, Hydrangeas and others)
  • In general, many shrubs will be growing rather quickly now and they may want to grow too large for their space.  This may be what you want, but if not they will need regular pruning to restrain them.  Pruning is best done just following their bloom cycle so as not to interrupt flowering.  For many shrubs this may be now.
  • This is about the time to prune winter and spring flowering vines that have finished blooming.  These include Pink Jasmine (Jasminum), Hardenbergia species (Lilac Vine), Jessamine (Gelsimium species), Cat’s Claw (Macfadyena unguis-cati), Flame Vine (Pyrostegia) and Wisteria (see separate entry).

Soil Care:

  • A healthy garden begins with the soil.  Investing in the soil, managing the soil and protecting the soil are its foundation.  Healthy soil is living and breathing, teaming with earthworms, microorganisms, beneficial fungi, bacteria, microbes and other invisible life.
  • A thick layer of organic mulch, averaging about two inches should be maintained on top of the soil nearly year-round.  This is an excellent month to add additional mulch as needed to maintain this level.  This organic mulch layer will cool the root systems from the hot temperatures ahead, reduce irrigations, reduce weed problems, and improve both soil life and soil quality.
  • If you have been considering inoculating your soil with beneficial mycorrhizae, this is a perfect month in which to do it.  The soil temperatures are just right for quick establishment.  This can be done quickly and easily in established areas by using mycorrhizae “tablets”.  In moist soil, poke a hole near the plant with a ½” or ¾” rod or stick.  Drop a tablet into the hole and push it in again with the stick.
  • Do not use of very high analysis fertilizers in a garden, especially phosphorus.  These formulations will inhibit or even destroy much of the soil life that is so vital to a healthy sustainable soil.  Do not use soil-applied systemic fertilizer/insecticide combinations, which are very damaging to soil life.
  • Use insecticides only when necessary and even then use the least toxic product available.  Many of these products move into the soil and interfere with invisible soil life.
  • If you can, begin a compost pile or purchase a compost bin.  Leaves, clippings, kitchen scraps, and many other ingredients can be composted and returned to the garden.  Home compost is one of the very best ingredients you can add to your soil.  The benefits are huge in the areas of disease suppression, increasing beneficial microorganisms, improving soil structure and texture, nutrient retention and nematode suppression.
  • If your soil PH is too high (alkaline) this is one of the better months of the year to lower it.  Two methods are both effective.  Using a low PH mulch over the surface is probably the most effective.  The other is with the incorporation of soil sulfur, an organic naturally occurring acidifying chemical.
  • Sweet Peas:
  • These should still be in full bloom about now.  Keep the flowers trimmed regularly to encourage more flowers.  This may be as often as twice a week.  Sweet peas are one of the plants that really benefit from having their flowers trimmed.
  • Feed regularly.
  • Assist them with climbing and support if necessary.

Trees:

  • (See also the information under Avocados, Citrus and Deciduous Fruit Trees)
  • This is a good month to prune tender sub-tropical trees (like Ficus, Coral Tree, Avocado, Citrus, etc.).  Sub-tropical trees should not be pruned during cool winter months.  However, care must be taken not to disturb nesting birds at this season.
  • This is a very good time to plant most tender, subtropical trees like coral tree (Erythrina), orchid tree (Bauhinia), trumpet tree (Tabebuia) and others.
  • Many trees may be suckering heavily now.  Remove these suckers below ground by pulling them.  If you cannot pull them, dig them to the point where they are attached to the tree and cut them flush with the root or trunk, leaving no “stub”.

Tropicals & Subtropicals:

  • (See also the information under Avocados and Citrus)
  • Most of these are just waking from the cool months.  It is still early for most of these.  Some varieties will be showing signs of new growth.  Depending upon your location and the species involved, you may be able to begin some plantings.
  • Most varieties can be fertilized now, but any that look completely asleep still should wait another month.
  • Watering can usually be more frequent as the plants wake and begin growing.

Tuberous Begonias:

  • Tubers should be sprouting in the flats that you put them into last month.
  • When there is about two to three inches of growth on each tuber gently scoop it out of the tray with a spade.  Place it into a basket, pot or well drained bedding area where it will grow and bloom for the rest of the summer and into the fall.
  • Begin fertilizing.  Tuberous begonias are heavy feeders, especially in containers.  Use a well balanced fertilizer and periodically alternate with an acid formulation.
  • Keep them well watered, but not soggy.  The soil should be rich and well-drained.

Vegetables:

  • There is still time to plant artichokes from gallon containers and get fruit this year.  Remove any suckers from returning plants.  A single crown will produce larger fruit.  The suckers can be given away to friends or re-planted elsewhere.
  • Early potatoes from those planted last fall may be ready for harvest. Mound spring potatoes that you planted last month.
  • Successive plantings of many vegetables will insure a constant supply.
  • In a well established asparagus patch, this is still a good time to harvest asparagus spears.  Don’t take any spears during the first two years after planting.
  • Warm-season vegetables can be planted.  Use transplants or seeds for beans, celery, cucumbers, eggplant, okra, peppers, salsify, squash, sunflower and tomatoes.  Corn, lima beans, jicama, melons and pumpkin are planted from seed.
  • Early this month may be the absolute best time to plant tomatoes from transplants.  A crop planted now will produce for several months.
  • Plant corn from seed this month.  Because corn needs to be cross-pollinated it must be grown in clumps or rows.  Twelve plants are about the minimum for good pollination and twenty or more is better.  Plant crops successively every three to four weeks for a continual harvest.
  • Along the immediate coast most cool-season crops like arugula, lettuce, peas and members of the cabbage family can still be grown.  Alternatively, the real heat-loving vegetables like corn, melons, peppers and pumpkins should be grown in front of a hot south facing wall.
  • Beets, carrots, chard, radish and turnips can be planted just about year-round.
  • Since most annual vegetables are shallow rooted and quick growing, feed them regularly with a well balanced organic fertilizer

Wisterias:

  • This is the main month of bloom for wisterias.  If proper pruning was followed all year, established plants should be in full, glorious bloom now.  Enjoy.
  • Select and plant new wisterias now, while they are in bloom.  Grafted plants are preferred, since they will almost always bloom at a much younger age.
  • There is still no need to fertilize now and irrigation is only needed on young, newly installed plants.