This Month in Your Zone 5 Garden: December
Short answer: no more lawn fertilizer after November 30, water evergreens before the ground freezes, put winter mulch down once it does, and keep the Christmas tree and poinsettias away from heat. Here is the December list for Cohoes and the Capital District.
Lawns: the fertilizer season is over
New York law does not allow fertilizer of any kind on lawns from December 1 to April 1, and never within 20 feet of water (NY Environmental Conservation Law §17-2103). That makes November 30 the last day to feed a lawn this year.
Arborvitae and evergreens
- Water well before the ground freezes. A good soak going into winter is the best-supported defense against winter burn (brown, dried-out foliage). Anti-desiccant sprays have weak evidence behind them, so don’t count on one instead of water.
- Tie uprights against snow. Wrap upright arborvitae, yew and upright juniper loosely with twine in fall so heavy snow doesn’t split them open. Take the twine off in spring.
- Deer. Deer hit arborvitae and yew hardest in winter. Fencing is the most reliable fix; repellents work poorly in freezing weather.
More on planting and spacing: arborvitae privacy hedge.
Winter mulch, roses and hydrangeas
- Wait for the ground to freeze, then spread 2–4 inches of mulch. Winter mulch isn’t there to keep plants warm — it keeps the soil from freezing and thawing over and over, which heaves plants out of the ground.
- Roses: mound 6–8 inches over the base.
- Hydrangeas: bigleaf hydrangeas benefit from a windbreak. Panicle hydrangeas are fine on their own.
- Keep mulch pulled back off trunks and stems.
Troy’s sells bulk mulch by the yard — see how much mulch you need.
Christmas tree care
- Give the trunk a fresh, straight cut and put it in water right away.
- Check the water every day. A fresh tree drinks the most in its first few days.
- Plain water is all it needs — additives don’t help.
- Keep it away from heat vents and fireplaces.
Trees, wreaths and holiday hours: Christmas at Troy’s. More detail: keeping a Christmas tree fresh.
Poinsettias
- Keep them at 60–70°F, out of drafts and away from heat vents.
- Poke holes in the foil wrap so water can drain.
- When it’s under 50°F outside, wrap the plant for the car ride home.
Holiday plants and pets
From the ASPCA’s plant list:
- Poinsettia — irritating to the mouth and stomach, but its toxicity is generally overrated.
- Christmas cactus — non-toxic to dogs and cats.
- Amaryllis — toxic to dogs and cats. Keep it out of reach.
Ice melt, walkways and pavers
- Most plant damage from ice melt comes from using too much. Use only what you need.
- CMA (calcium magnesium acetate) is much safer for plants, but it costs more and works down to about 5°F.
- Sand gives traction without any salt.
The same goes for patios, paver walkways and steps: go light on ice melt, and use sand when you just need grip.
Questions? Call or stop in
Call (518) 785-1526 or stop in at 1266 New Loudon Rd, Cohoes. Hours now: Mon–Sat 8–4 · Sun 9–2. Closed Nov 26 — Thanksgiving. Holiday & seasonal hours.