How to Protect Tomatoes on Cold Nights?

Tomatoes are a delicious summer treat, yet nighttime temperatures can dip dangerously low for these heat-loving plants. Protecting tomatoes from the cold protects your investment in time and effort.

Follow these tips to keep your tomatoes cozy on chilly nights:

1. Know When to Worry

Temperatures below 50°F can damage tomatoes. Once nighttime lows drop into the 40s, it's time to take action.

Tomato leaves show cold damage first. Leaves turn limp spooky purple when chilled. Stems and branches become extra flimsy. If cold lasts long, growth stops completely.

Frost seriously harms tomatoes. Temperatures below 32°F freeze cells, rupturing tender skins. This mushy black ruin means demolished harvests.

So intervene before nights get frosty. Mid 40s demand protection. Upper 30s require immediate action.

2. Choose Cold Hardy Varieties

Some tomatoes tolerate cold better than others. Seek out hardy options suitable to your zone.

• Small fruited tomatoes asist cold excellently. Try grape or cherry types.
• Determinate varieties handle cold better than spreading indeterminates. Plant short bushy Romas or compact celebs.
• Heirlooms lack hybrid vigor, yet some persevere where others falter. Ask neighbors which oldies endure early frosts.
• Container plants need extra protection. Pick early producers like Siberian, Gonzales, or Oregon Spring.
• Beefsteak tomatoes succumb to cold fast. Avoid planting these heat lovers unless you plan to protect them.

3. Warm the Soil

Tomato roots don't like chilly soil. Cold earth stunts growth for months after.

Warm their beds before frost threatens.

• Black plastic mulch adds degrees by trapping daytime heat. Lay it weeks before last frost date.
• Water warms as it absorbs sunlight. Deep daily drinks keep roots toasty.
• Walls radiate stored solar energy at night. Plant beside brick or stone to block wind and keep warmth in soil.
• Build fast draining, raised beds. Elevated soil thaws quickly come sunrise.
• Add old wallpaper under mulch. The paper blocks evaporation so earth stays warmer.

4. Insulate Plants

Protect above ground growth from direct cold.

But avoid total wraps that trap in moisture! Air circulation is crucial to prevent diseases.

Here are insulating options:

• Floating row covers are the go-to for cold snaps. Drape these lightweight blankets directly over plants, securing the edges with weights or ground pins.
• Reusable cold frames are mini greenhouses placed atop plants. Close the lids at dusk and open after sunrise so plants get fresh airflow.
• Use old sheets or frost blankets. Top plants at dusk and remove in morning.
• Surround with plastic jugs filled with hot water. Replace with fresh hot water in the morning. The jugs radiate warmth through the night.
• Wrap plants individually with newspaper or old sheets, leaving top uncovered. Tomato cages make handy support frames.
• Build mini tents from wooden stakes and clear plastic. Ventilate the ends by propping up the plastic.
• Create larger enclosures using PVC hoops and plastic sheeting. Ventilate one end.
• Mulch heavily around plants using grass clippings or raked leaves. 4+ inches provides insulation.

5. Add Supplemental Heat

When nights dip into the 30s, passive protection may not suffice. Outright heat is needed to raise temperatures.

Here are sources of extra warmth:

• Place old-fashioned string lights under plant covers. The bulbs generate gentle ambient warmth.
• Use a space heater under protective structures, taking care not to scorch plants with direct heat.
• Fill cups with cooking oil and float candle wicks or cheap tea lights. Position these “tomato candles” near plants.
• Line paths with sand filled buckets or tubes. The sand absorbs sunshine during the day and slowly releases heat at night.
• Mix up tank sprayers of compost “teas” in the morning. As the brews decompose during day, they heat up. Spray brews onto plants in evening.

6. Manage Irrigation

Too much moisture makes cold damage worse! Wet foliage freezes faster than dry leaves.

Prevent bursting cells by hardening plants before frosts:

• Water deeply 1-2 weeks pre-cold then taper off irrigation.
• Stop fertilizing 2 weeks before expected frost. Fertilizer promotes soft growth.
• Prune leaves 1-2 weeks before to remove excessive moisture and increase airflow.
• Avoid watering for 2 days preceding cold nights.
• Water in morning after frost danger passes so soil warms faster.

7. Be Ready to Cover Fast

Prediction is imperfect! Frost can strike earlier than forecast. Sudden cold snaps wait for no gardener.

Don't scramble when temps plunge. Prepare covers beforehand:

• Assemble simple frames over beds from PVC or stakes to hold row cover, plastic or sheets.
• Gather bricks, boards, cinder blocks to weight covers. Have extras handy.
• Buy repair supplies like duct tape, staple gun, zip ties, binder clips, safety pins.
• Locate your headlamps or outdoor lighting. You may be covering plants in dark.
• Keep old towels or rags for drying foliage or wiping frozen condensation.

Stay alert to forecasts. Check predicted lows twice daily seven to ten days prior. When low 40s loom, preemptively cover plants. You can always uncover if unneeded. Better safe than sorry with frost!

Your diligent efforts will be rewarded with armloads of ripe tomatoes before fall frosts end the season. A small nightly routine preserves months of sunny growing and juicy tangy sandwiches. Don't let one frigid night ruin a whole summer’s growth! Follow these tips to protect tomatoes from cold and enjoy their bounty long past summer solstice.

Conclusion

Protecting tomatoes from cold nights requires foresight and action. Choose hardy varieties adapted to your zone. Build warming foundations using raised beds, stones, plastic mulch and organic matter. Insulate plants at dusk, allowing for air circulation. Add supplemental heat from lights, candles or compost. Water judiciously to harden plants before frost. Prepare covers ahead of time for rapid response. With smart preventative care, your tomatoes will bear right up until first frost!

Tips to protect tomatoes on cold nights:

1. Select cold-tolerant tomatoes varieties
2. Warm soil with black plastic, stones, raised beds
3. Insulate above-ground growth with row covers, sheets
4. Allow for airflow to prevent disease
5. Add supplemental heat from lights or candles
6. Reduce watering to harden plants before frost
7. Assemble covers beforehand for quick protection
8. Stay alert to weather forecasts for cold snaps

Hardening plants, insulating beds, and supplying warmth can gain weeks of harvest. With proactive measures, your tomatoes will thrive despite cold autumn nights!