Twin Oaks Garden Task List for April

Asparagus in early April.Credit Wren Vi
Asparagus in early April.
Credit Wren Vile

All Month:

Lettuce Factory: In flats, (on greenhouse bench) sow lettuce #7, 8, 9 (romaines & small varieties to interplant with peanuts). Transplant 1/3 bed lettuce (120 plants)/week. Plant #4, 5, 6 this month.
Compost Needed for April: 6-9 tractor buckets for beds, 24-30 bkts to disk in.

Early April:

In greenhouse, sow lettuce #7;

Keep celery above 55°F, and celeriac above 45°F (don’t put in coldframe). 10 consecutive days <55°F for celery, <45°F for celeriac, causes bolting.

Spot lettuce, harden off in coldframe. Spot peppers, tomatoes, & eggplant. Protect new pepper seedlings from mice.  Keep tomatoes above 45°F at night, eggplant above 55°F.

Cut sweet potato slips at 6-12”, put in water.  Once a week, plant rooted slips in 4” flats.

Sow outdoors: carrots #5, beets (see March notes), parsnips with radishes #2, (in celery bed), sunflowers.

Weed and thin early crops. Side dress or foliar spray over-wintered spinach to boost production.

Take rowcover from turnips, senposai, cabbage #1, kohlrabi, little alliums, onions as needed for broccoli.

Transplant lettuce #4, main cabbage & broccoli under rowcover (12 pieces) within 6 weeks of sowing.

Till beds for mid-April. Compost beds for late April plantings.

Garlic bulbing is initiated on/after April 10 (13 hours daylight), and soil temperature above 60°F.

Mid April:

In greenhouse sow melons #1 in soil blocks or plug flats, replacement paste tomatoes, lettuce #8, and okra.

Sow beans #1 when lilac in full bloom, sunflowers. Sow edamame #1, corn#1, if warm, and soil >60F.

Till beds for late April (chard, cowpeas, peanuts). Compost beds for early May (okra, toms, melons, celeriac, lettuce 7,8,9, asparagus beans)

Hill up potatoes when 6” high. Cover half the vine. Repeat after 2 weeks. (Flameweed if too wet to hill.)

Take rowcover from kale, collards, early lettuce for raised bed tender crops.

Transplant broccoli #2, insectary flowers #1, bulb fennel, lettuce #5, cukes #1 w/nasturtiums, zukes #1; use spring hoops for cucurbits. Take rowcover from spinach to strawberries.

A fine bed of fava beans. Credit Kathryn Simmons
A fine bed of fava beans.
Credit Kathryn Simmons

Install stakes every 8-10’ for peas and fava beans, and stringweave them to final height of that variety.

Weed garlic [or flameweed it early in the morning after a good rain. Direct flame at base of garlic plants]

Harvest lettuce as heads rather than leaves, from 15 April

#3 Spring Tractor Work (mid April) – Disk areas for sweet potatoes, winter squash, watermelons, (Romas and peppers if no-till cover crop insufficient). Bush-hog late food crop plots when rye heads up, to help clover or peas develop. Also clover patches, eg Green Fallow (All Year Cover Crops).

Late April:

in greenhouse sow lettuce #9; watermelons #1 & 2 in soil blocks or plug flats; calendula and various insectary flowers, filler corn & Romas.

Sow corn #1 (1/2-3/4” deep) in two phases, and peanuts if soil temperature is 65°F. Also cowpeas #1, and sesame.

Sow more leeks if needed in Little Alliums bed outdoors. If not, sow more mini-onions and scallions #3.

Transplant lettuce #6, leaf beet, chard, insectaries; finish transplanting gaps in the main broccoli & cabbage plot, plant Alyssum. Take rowcovers from broccoli & cabbage for new crops.

If mild, plant tomatoes. Harden off nightshades by restricting water.

Till beds for early May (okra, toms, melons, celeriac, lettuce 7/8/9, asparagus beans). Compost beds for mid-May (edamame, eggplant, limas).

Store spring and fall seeds (spinach, peas, beets) in the basement for the summer.

Foliar feed the potatoes, ideally the morning before hilling up, and every 2 weeks.

Roll out Driptape and Biotelos corn plastic mulch for peppers and Romas where no-till cover crop not used.

Cover crops: sow rye to wimp out. Sow buckwheat in any beds not needed for at least 5 weeks eg. leeks limas; add soy if bed not needed for 7 weeks. 

Haybine or bush-hog vetch & rye for no-till planting of Roma paste tomatoes, late in the month (or very early in May). (Mow strips; or till strips through the cover crop for the rows, with narrow-set tiller). Water the area before digging holes, if dry.

Perennials: Weed blueberries, asparagus, raspberries, strawberries, grapes as needed. Mow aisles. If asparagus weeds are getting out of hand, mow down one or more rows to keep control. Monitor asparagus beetles, spray spinosad when bees not flying, if >10 adults/100 crowns. Spinosad: Shake well, 1-4 Tbsp/gall (1fl.oz=2Tbsp=30ml.) Repeat in 6 days.

The black center of this strawberry flower show that it was hit by frost and no berry will develop.Credit Kathryn Simmons
The black center of this strawberry flower show that it was hit by frost and no berry will develop.
Credit Kathryn Simmons

Cover strawberries if frost threatens – take rowcovers from spinach. (Pick flowers off any new spring  plantings.)

Visit grapes, log progress, remove flower buds from new vines. Note deaths and where replacement arms are needed.  Check and repair fruit drip irrigation, thin raspberries to 6/foot of row.

Harvest and weed: Asparagus, chard (hoophouse), collards, garlic scallions- pull at 8″, kale, leeks, lettuce, radishes, rhubarb, senposai, snap peas in hoophouse, spinach.

Starting Seedlings

Seed flats in the greenhouse
Seed flats in the greenhouse

We’ve been starting seedlings since late January, and the greenhouse is filling up with flats of lettuce, cabbage, kohlrabi, spinach, scallions and broccoli. We’re eating our way through the lettuces that grew overwinter in the compost in the block-work greenhouse beds, and shoveling out the compost to fill our flats. All our seedlings are grown in 100% home-made compost. We screen compost to fill the beds in September and transplant lettuce there in October. When we need the compost for the seedlings, it has mellowed nicely and has plenty of worms. This beats buying in bags of compost, or chipping lumps off a heap of frozen compost outdoors in January! Our greenhouse has a masonry north wall and a patio-door south wall. It has no heating apart from the sun (this is Zone 7). This space is warm enough and just big enough for all our seedlings once they have emerged. For growing-on the very early tomatoes and peppers, destined for our hoophouse, we use an electric heat mat and a plastic low tunnel in one corner of the greenhouse. Many seeds benefit from some heat during germination and are then moved into slightly less warm conditions to continue growing. This means it’s possible to heat a relatively small space just to germinate the seeds in. We use two broken refrigerators as insulated cabinets, with extra shelves added. A single incandescent lightbulb in each supplies both the light and the heat (we change the wattage depending on what temperature we’re aiming for). Some people construct an insulated cabinet from scratch, with fluorescent lights suspended above the flats.

Our coldframes and greenhouse
Our coldframes and greenhouse

We use traditional coldframes for “hardening-off” our plants (helping them adjust to cooler, brighter, breezier conditions). They are rectangles of dry-stacked cinder blocks, with lids of woodframed fiberglass. Having heavy flats of plants at ground level is less than ideal for anyone over thirty-five! Shade houses and single-layer poly hoop structures with ventable sidewalls and benches for the flats are a nicer option. Some growers report that some pests are less trouble when flats are up on benches. Others say flats on the ground produce better quality plants. According to the nighttime temperatures, we cover the coldframes with rowcover for 32°F–38°F (0°–3°C), add the lids for 15°F–32°F (–9°C–0°C) and roll quilts on top if it might go below 15°F (–9°C). For brassicas, lettuce and our paste tomatoes (a big planting), we use open flats — simple wooden boxes. The transplant flat size is 12″ × 24″ × 4″ deep (30 × 60 × 10 cm). It holds 40 plants, “spotted” or pricked out in a hexagonal pattern, using a dibble board. For sowing, we use shallower 3″ (7.5 cm) flats. Usually we sow four rows lengthwise in each seedling flat. We reckon we can get about six transplant flats from each seedling flat. This allows for throwing out any wimpy seedlings, and lets us start a higher number of plants in a smaller space. Because we transplant by hand, and because we hate to throw plastic away (or spend money when we don’t need to), we use a range of plastic plant containers. For crops where we are growing only a small number of plants of each variety, we use six- or nine-packs, or a plug flat divided into smaller units.

One year we tried soil blocks for early lettuce transplants, shown here on our custom-made cart
One year we tried soil blocks for early lettuce transplants, shown here on our custom-made cart

The first crops sown are not necessarily the first ones planted out. Our spinach gets sown Jan 24 and transplanted out 4 weeks later. The early tomatoes get planted in the hoophouse at 6 weeks of age (slower-growing peppers go in at 7.5 weeks with rowcover at the ready!). Lettuce goes outdoors after 6.5 weeks, cabbage after 7.5 weeks, cipollini mini-onions after 8 weeks. These are early season timings and as the days warm up and get longer, seedlings grow more quickly. Being a few days later sowing something in early spring makes little difference, as later sowings can catch up by growing faster in the warmer weather. If the spring is cold and late, you may find your greenhouse packed to the gills with flats you don’t want to take outside. We try to put the faster-maturing crops near the doors and keep the open flats, which will need spotting-out, near the accessible north side. But let’s not complain about the bounty of so many plants! Spring is an exciting time of year, full of new growth and new potential. Working in the greenhouse with tiny plants on a sunny day when it’s cold outside is a special treat.