January garden tasks: Northeast and Long Island

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Take stock of your seeds

Before ordering, sort what you already have. Most vegetable seed stays usable for a few years when stored cool and dry, but germination drops over time. Onion, leek and parsnip seed are notably short-lived, and old packets of these are often not worth keeping.

Run a germination test on anything older than a year or two. Cornell's seed germination testing guide describes the method:

1. Count out 10 seeds and spread them on a damp paper towel.
2. Roll the towel up, slip it into a plastic bag, label it, and set it somewhere warm, such as the top of the refrigerator.
3. Check it after the germination time printed on the packet and count the sprouts. If 8 of 10 sprout, germination is 80%. Below about 50%, sow more thickly or replace the seed.

Store saved and leftover seed in a sealed jar in a cool, dry place. Heat and humidity shorten seed life faster than anything else.

Order seed and plan the beds

Order in January, before popular varieties and seed potatoes and onion sets sell out. As you plan:

• Rotate crop families. Avoid putting tomatoes, peppers and eggplant (one family), squash and cucumbers, or cabbage-family crops in the same spot they occupied last year. This is where the garden record from December pays off.
• Choose disease-resistant varieties for your known problems, such as early blight and septoria on tomatoes or powdery mildew on squash and cucumbers. Seed catalogs list resistance codes.
• Choose varieties for your season length. Gardeners in zone 5 should look for shorter days-to-maturity on tomatoes, peppers, melons and winter squash. Long Island has a longer season and more room to choose.
• Buy seed garlic and potatoes from regional growers who sell certified disease-free stock, and order early for spring delivery.

UConn's Home and Garden Education Center recommends planning the garden on paper in January, with spacing worked out before you buy, so you order only what fits.

Build a seed-starting calendar

Every indoor sowing date comes from your average last frost date. The March guide gives approximate Northeast dates: New York City around April 1–7, Long Island around April 7, Boston April 15–20, Hartford around April 20, Albany around May 1 and Portland, Maine around May 7. Check your own with the frost date tool. Then count back using the timing in Starting Plants Indoors and the seed packet:

• Onions, leeks, celery: 10–12 weeks before last frost. That is mid-to-late January for Long Island, late January to early February for zone 6, and February for zone 5.
• Peppers and eggplant: 8–10 weeks before. Mid-February to early March in zone 7.
• Tomatoes: 6–8 weeks before. Early to mid-March in zone 7. Starting them earlier gives leggy, overgrown transplants.
• Broccoli, cabbage, lettuce for transplanting: roughly 4–6 weeks before they go outside, which for these frost-tolerant crops is several weeks before the last frost.

Write the dates on a calendar now so nothing gets started too early just because the seed packets have arrived. Our seed starting guide covers setup.

Start onions and leeks (zone 7)

On Long Island and in the New York City area, late January is when to sow onions, leeks and celery indoors. Gardeners in zones 5–6 can get their supplies ready now and sow in February.

• Light: put seedlings under lights, not just a window. The March guide cites Penn State's recommendation of lights 2–4 inches above the seedlings for 14–16 hours a day. January window light is too weak and too short.
• Medium: use a sterile seed-starting mix, not garden soil. See seed-starting mix vs potting soil.
• Sowing: sow onion and leek seed thickly in a flat or cell tray. When the tops pass about 4–5 inches, trim them back to around 3 inches. The plants grow stockier and easier to handle.
• Cleanliness: wash reused trays and pots in a dilute bleach solution to reduce damping-off.

Check stored bulbs, produce and forced pots

Once a month through winter, check everything in storage:

• Dahlias, cannas, gladiolus: per Penn State Extension, dahlia tubers should be kept cool and frost-free. Throw out any that are soft or moldy. If tubers are shriveling, lightly mist the packing material. If they are damp, let the material dry out. See overwintering dahlias.
• Geraniums and other tender perennials being kept indoors: cut back leggy growth and water sparingly. See overwintering geraniums.
• Squash, onions, potatoes: remove anything soft or sprouting before rot spreads.
• Pots of forced bulbs: keep the soil lightly moist. Bring pots into warmth once shoots are a couple of inches tall and the cold period on the label has passed.

Lawn and tool prep

Lawns need almost nothing in January, but a few points are worth knowing:

• Stay off frozen or frosted turf. Foot traffic on frozen grass crushes the crowns and leaves brown footprints in spring.
• Do not fertilize. Lawn fertilizer is off-limits until April 1 in Suffolk County, per Suffolk County's Healthy Lawns, Clean Water program, and statewide in New York. New Jersey's homeowner blackout runs until March 1. Fertilizer on frozen ground mostly washes away.
• Lime recommended by a fall soil test can go on lawns and garden beds during a thaw, when the ground is not frozen or saturated.
• Plan crabgrass timing. Pre-emergent goes down when forsythia blooms, typically mid-March or later, as the March guide explains. Buying it now is fine. Applying it now is wasted.

Sharpen pruners, loppers and saws now, before late-winter pruning season. Clean, sharp blades make cuts that seal faster.

Outdoor checks on thaw days

• Frost heaving: after a thaw, look for perennials, especially fall-planted ones, pushed up out of the soil. Press them back down gently once the soil softens and add mulch.
• Animal damage: look for chewed bark at the snow line on young trees and fresh browse on yews and arborvitae. Raise trunk guards if snow has piled up past them, and reapply repellents on days warm enough for them to dry.
• Snow load: brush heavy snow off evergreens from below, and leave ice alone.
• Salt: keep shoveled, salty snow off beds. On Long Island, a heavy rain or snowmelt helps flush salt out of sandy soil.
• Black knot on plums and cherries: the swollen black galls are easy to spot on bare branches. Mark them now and cut them out several inches below the gall during dry winter weather, then throw out the prunings.
• Winter sowing: many native perennials and hardy annuals germinate best after a cold, moist period outdoors. Michigan State University Extension describes sowing them in covered containers left outside, and late January is a good time to start. See the winter sowing method.

Leave fruit-tree and shrub structural pruning until late winter, as covered in the February guide.

Common mistakes

Frequently asked

Can I start any vegetable seeds in January?

In zone 7 (Long Island, NYC), onions, leeks and celery can be sown indoors in the second half of January because they need 10–12 weeks before transplanting. Nearly everything else is still too early. In zones 5–6, wait until February.

How long do vegetable seeds last?

It varies by crop and storage. Onion, leek and parsnip seed fades fast. Tomato, cabbage-family and squash seed often lasts several years if kept cool and dry. A 10-seed germination test tells you more than the date on the packet.

Is it okay to prune fruit trees in January?

Removing dead, broken or black-knot-infected wood is fine. Save structural pruning of apples and pears for late winter, February through March, when the worst cold has passed. Prune peaches last, close to bloom.

What should I do if my perennials heaved out of the ground?

Gently press them back once the soil thaws enough to work, cover the exposed roots with soil, and add winter mulch to keep the ground frozen afterward. Fall-planted perennials and shallow-rooted plants such as heuchera are most prone to heaving.

Sources

1. Seed Germination Testing: Easy and Thrifty, Cornell University (Fruition blog)
2. Starting Plants Indoors, Cornell Cooperative Extension
3. Planning Your Gardens Early and Other January News, UConn Home and Garden Education Center
4. Don't Ditch Those Dahlias: Easy Tips for Winter Storage, Penn State Extension
5. Seed Starting 101, Rutgers Cooperative Extension of Cape May County
6. Healthy Lawns, Clean Water Fertilizer Reduction Program, Suffolk County, NY
7. Winter Sowing in Containers for Michigan Gardeners, Michigan State University Extension

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