HOW TO GROW SQUASH AND ZUCCHINI

by | Feb 21, 2026

Squash and zucchini are warm-season crops that grow fast and produce heavily with the right care.

When to Plant

  • Plant after last frost

  • Soil temperature: 70°F+

  • In Nashville area: typically late April–May

  • You can plant again in mid-summer (July) for fall harvest

Sun & Soil

  • Full sun (6–8+ hours daily)

  • Rich, well-draining soil

  • Mix in compost before planting

  • Ideal pH: 6.0–6.8

Heavy feeders — they love fertile soil!

How to Plant

  • Space 2–3 feet apart (bush types)

  • Space 3–4 feet apart (vining types)

Watering

  • 1–1.5 inches per week

  • Water deeply at the base

  • Avoid overhead watering (helps prevent powdery mildew)

  • Mulch to retain moisture and reduce disease

Pollination Tips

Squash plants produce:

  • Male flowers (long thin stems)

  • Female flowers (tiny squash at base)

If flowers drop without fruit forming:

  • Encourage pollinators

  • Avoid spraying during bloom

  • Hand pollinate if needed (transfer pollen from male to female flower)

Common Problems & Solutions

Squash Vine Borers

  • Sudden wilting

  • Prevent with row covers early season

  • Wrap lower stems in foil

  • Inject BT into stem if needed

Squash Bugs

  • Bronze eggs under leaves

  • Hand remove eggs

  • Use neem oil early

Powdery Mildew

  • White powder on leaves

  • Improve air flow

  • Remove infected leaves

  • Spray diluted milk (1:10 milk:water)

Harvesting

Zucchini & Summer Squash

  • Harvest at 6–8 inches long

  • Pick frequently (every 1–2 days)

  • The more you harvest, the more it produces

Companion Plants

Good companions:

  • Nasturtiums (trap pests)

  • Radishes (deter beetles)

  • Dill

  • Borage

Avoid planting near potatoes.

Heat Tips (Important for Tennessee Summers)

  • Afternoon shade helps in extreme heat

  • Water deeply during drought

  • Mulch heavily

  • Production may slow in extreme heat but resumes when temps drop

Squash & Zucchini Pest ID + Prevention Chart

Pest What It Looks Like Damage Signs When It Shows Up Prevention Treatment
Squash Vine Borer Moth (orange/black), white grub inside stem Sudden wilting, hole in stem, sawdust-like frass Late May–June Row covers early season, wrap stems with foil, plant early or late crop Inject BT into stem, slit stem & remove larva, mound soil over wound
Squash Bugs Gray/brown shield-shaped bugs, bronze egg clusters under leaves Yellow spots, wilting, blackened leaves Early–mid summer Hand-remove eggs, keep garden clean, use row covers Neem oil (early stage), hand pick adults
Cucumber Beetles Yellow with black stripes or spots Chewed leaves, bacterial wilt Late spring onward Floating row covers, trap crops (radishes), mulch Neem oil, sticky traps
Aphids Tiny green/black clusters on stems & leaf undersides Curled leaves, sticky residue Throughout season Encourage ladybugs, avoid excess nitrogen Spray with strong water stream, insecticidal soap
Spider Mites Very tiny, fine webbing Speckled yellow leaves, dry appearance Hot, dry weather Keep plants well watered, rinse leaves Hose off undersides regularly
Cutworms Fat gray/brown caterpillars in soil Seedlings cut off at base Early season Cardboard collars around seedlings Hand remove at night
Powdery Mildew (fungal) White powder on leaves Leaves yellow & die Humid late summer Good spacing, water at soil level Milk spray (1:10), remove infected leaves

Prevention Strategy Timeline (Tennessee Focus)

At Planting

  • Use row covers

  • Add compost

  • Install drip irrigation

  • Mulch

Early Growth

  • Check undersides of leaves 2–3x per week

  • Remove eggs immediately

  • Wrap stems to prevent borers

Mid-Summer

  • Increase airflow (prune lightly)

  • Water deeply during heat

  • Monitor for mildew

Pro Tip

Healthy plants resist pests better. Consistent watering and fertile soil make a huge difference.

How to Grow Squash Vertically

Growing squash vertically saves space, improves airflow (less mildew!), and makes harvesting easier — especially helpful in humid summers like we get around Nashville.

Pick a Strong Support

Squash gets heavy fast — flimsy tomato cages won’t hold up.

Good Options:

  • Cattle panel trellis (very sturdy)

  • A-frame trellis

  • Wooden frame with welded wire

  • Strong garden arch

  • Fence panel

Height: 5–6 feet is ideal
Install BEFORE planting so roots aren’t disturbed later.

Planting Setup

  • 2–3 feet between plants

  • Rich soil + compost

  • Mulch heavily

Water deeply at the base.

Train the Vines

When vines are 1–2 feet long:

  • Gently guide them onto trellis

  • Tie loosely with garden twine or soft clips

  • Check weekly and keep training upward

Zucchini (bush types) don’t vine much, but you can:

  • Remove lower leaves

  • Stake the main stem like a tomato

  • Tie upright as it grows

Benefits of Vertical Growing

✔ Better airflow → Less powdery mildew
✔ Easier pest monitoring
✔ Cleaner fruit
✔ Saves space
✔ Easier harvesting

Common Mistakes

❌ Weak trellis
❌ Waiting too long to train vines
❌ Overcrowding plants

Middle Tennessee Heat Tip

In extreme July heat:

  • Afternoon shade helps

  • Keep roots mulched

  • Water deeply 2–3 times per week

  • Production slows over 95°F but rebounds in fall