To-Do List - April

by Karen Bodner, MG
Vegetables

I heard about a great idea from a guy in Austria. He starts tomato seeds in plastic liter soda bottles with the top cut off (you could also transplant a small seedling). As the plant grows, he removes the lower leaves and fills the container with more growing medium. This, of course, creates great root systems and would save me from potting up in stages from 50-cell trays to 4-inch pots to gallon pots.

The tomatoes I have for my garden down south (Zone 8) are almost hardened off now and will be potted up into gallons if I don't get them in before the end of March. I will use the Red IRT plastic mulch with Gro-Therm and feel confident they will not experience stress.

Now, up here in our Zone 7 you can sow indoors. With few exceptions, veggies can be started indoors at this time. The exceptions would be those direct seeded into the garden in warm soil (corn, beans) and squash/melons that are transplanted a mere 3-4 weeks after sowing in pots.

Corn can be started in pots at end of month, if that is your method. However, timing is important, since you don't want to leave them in pots much longer than two weeks and certainly before they reach six inches. If their roots reach the bottom and begin winding around, growth will be adversely affected.

Harden off and transplant seed started earlier under open-ended plastic or slit plastic cloches (slit plastic works better for cool-season crops). Although most of these will grow without protection, they will get off to a better/faster start with it.

Sow directly outside: carrots, cabbage, lettuce/greens, onions, peas (inoculate and use enation-resistant varieties after April 1st), short-season Brussels sprouts, broccoli, beets, radishes, including Daikon, garden purslane, spinach, kale, and kohlrabi. Plant potato eyes later in month, if still mild. To achieve prize-winning garlics, sidedress them with a complete organic fertilizer mix this month.

Flowers and herbs

Remember to leave bulb foliage to die back before cutting or pulling out and do not bend, tie down or twist. If you started your perennials/biennials late, put them in the fridge for 1-2 weeks after a few sets of leaves are present; they may very well bloom this year. Start your tender annuals inside and direct sow hardy annuals, perennials herbs, and ornamental grasses outside. Pinch tips when 3-4 sets of true leaves are present to make bushy (well, not the grass, of course). Chrysanthemums and fuchsias will especially benefit from this practice; stop pinching 6 weeks before you want bloom.

Feed roses with balanced fertilizer. Cut leaves back on Pulmonaria to renew foliage not affected by powdery mildew (per Heronwood's Dan Hinckley). Pot up tuberous begonias and plant gladiolas and other hardy bulbs. It's now safe to plant dahlias. Monitor plants for disease if rains persist. Work one to two inches of well-composted manure or compost into flower beds two to three weeks before planting. Overwintering mulches should be removed gradually from around plants to let the soil warm up.

Vegetative propagation: On tip cuttings, remember they are very fragile, and it is important to place them in sealed plastic bags as soon as you take them. This type of cutting will also root more readily than at mature stages since growth is so active. We can envision totipotency in action as the cells at the cut end alter themselves to become roots! Tip cuttings should be nodal and about one and a quarter to two inches long and can be placed very closely in the rooting pots.


Take tip cuttings from Erysium, fuchsia, Helichrysum, Lavandula, and Salvia; basal cuttings from Ajuga, aster, Campanula, chrysanthemum, dahlia, delphinium, Euphorbia, Lavandula, Lysimachia, Monarda, phlox and Salvia to name a few. Lavender roots quite rapidly and should be potted up individually and given a liquid feed after about two weeks. Move overwintered plants raised from tip cuttings out to the garden (gradually, of course).

The following can be started by seed but will require heat to germinate properly: Achillea, Agapanthus, Alyssum, Gladiolus, Lobelia, Salvia and Tagetes, among others.

Fruits and nuts

Continue to plant new fruit trees, bushes, and berries. Keep them well-watered if nature doesn't. When container fruits come out of dormancy, feed with manure or compost tea and move them to a sunny location (with frost protection if necessary). Peach leaf curl may show up this month (check spray schedule). Spray for apple scab and cherry brown rot. Prune figs, plum trees, and young cherry trees (established trees should be done in summer). Cane and trailing berries should be fertilized with finished manure, compost or a commercial mix.

Trees and shrubs

Prune and fertilize spring-flowering plants after bloom. Mulch if necessary. Plant new trees and shrubs and keep well-watered. Monitor disease-prone plants for signs of pathogens. Pampas grass should be cut back to its framework before new growth starts. I torched mine first; this minimizes cutting and burns the blades which are sharp-edged.

Vegetative propagation: Tip cuttings can be taken from many favorite trees and shrubs: magnolia, Acer, clematis, fuchscia, Prunus, Vaccinium and Viburnum. Take basal cuttings from junipers. Overwintered plants raised from tip cuttings can be moved out to the garden. Once your heather cuttings show signs of growth, they can be potted into three-inch square pots in a peat-based compost and returned to the cold frame to continue growth. Your silver-leafed cuttings are now ready for the cold frame. Ventilate during the day. Pot up any rooted hardwood cuttings into three and a half-inch pots and return to cold frame.

General gardening

If soil is dry enough, work in overwintered cover crops two to three weeks before planting. Plant those treasures you pick up at nurseries as soon as possible; keep well-watered until established, and throw a handful of bone meal at the root zone when planting. Fertilize lawns with nitrogen just before some rain, and sow new lawns this month.

If it continues to rain, cover your beds with plastic if you can to allow them to dry out. It is important to elevate the plastic to allow evaporation; and, unless your soil is compacted clay, it can be ready to work in no time at all. If unable to elevate the plastic, try to pull it back on non-rainy days.

April IPM

And the season's dance begins once more! A few "big guns" appear this month to start wreaking havoc as they do so well. Adult codling moths will emerge some time this month, so place pheromone traps or check with Extension for official notification. Row covers over susceptible crops (cabbage, onion, carrots) are a huge deterrent to the carrot rust fly and cabbage maggot. The bark beetle adult takes flight May 1st; this is the worst enemy of living conifer trees.

Also look for tiny white grasshopper nymphs. They are fairly easy to smoosh since they don't move as quickly as the adults. Some insects will appear at the very end of the month (e.g., tachinid parasite and cabbage looper adults, however, the looper adult moth is nocturnal). Others are gone after the first week (e.g., stink bug adult). If you have a particular pest you're concerned about, you can research further. The book in the MG office entitled Insects and Mites of Economic Importance to the PNW has a detailed month-by-month calendar of all stages.

A =Adult E =Egg, P =Pupa, L =Larva, N =Nymph Beneficials are italicized.

rove beetles-A/E
western damsel bug-A
big-eyed bug-A
butterfly caterpillars-P/L
minute pirate bug-A
green lacewing-P
ladybeetle-A
syrphid fly-A/P
tachinid parasite-A/P
wasp parasite-A/E/P/L
predator mite-A
cinnabar moth-P
honey bees-A/E/P/L
alfalfa leafcutting bee-L
aphids-E/N
onion thrips-A
beet leafhopper-E/N
carrot rust fly-A/P
symphyllans-A/E
green peach aphid-A/E/N
wireworm beetle-A/L
cucumber beetle-A/E/L
asparagus beetle-A/E
variegated cutworm-P/L
western cherry fruit fly-P
peach twig borer-P/L
peachtree borer-L
apple aphids-A/N
codling moth-A/P
corn earworm-P
imported cabbageworm-A/P
cabbage looper -A/P
cabbage maggot-P
cabbage aphid-A/N
cabbage flea beetle-A
pear sawfly-A/E/P
pear psylla-A/E/N
root weevil-P/L
spider mites-A/E/N
pea weevil-A
greenhouse whiteflies-A/E/N
elm leaf beetle-A
bark beetle-A (flight 5/1)
white grub beetles-A/L
bean and currant aphids-A/N
stink bugs-A/E/N
pea aphid-E/N
western flower thrips-A/E/N
onion maggots-P
leafroller-L/P
filbertworm-L
filbert leafroller-E/L
raspberry crown borer-L
strawberry aphid-A/N
holly and soft scale-A/N
rose leafhopper-N
grasshopper-E/N
strawberry crown moth-P/L
western raspberry fruitworm-A/E/L
San Jose scale-E/N
oyster shell scale-N
slugs-A/E & young
walnut husk fly-P
sod webworm-L/P
fall webworm-P
box elder bug-A/E
seed corn maggot-A/P

 

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