What To Grow In A Mississippi Greenhouse Each Season

Greenhouses give Mississippi gardeners the power to extend seasons, speed up starts, and grow crops that would otherwise struggle in the state’s humid subtropical climate. With mild winters, hot humid summers, and occasional cold snaps in northern counties, planning what to grow in a Mississippi greenhouse requires attention to temperature, humidity, shading, and timing. This article lays out practical, season-by-season recommendations, cultivar choices, and care techniques so you can maximize production and quality year-round.

Greenhouse basics for Mississippi gardeners

Before diving into seasonal lists, set up and manage your greenhouse for Mississippi conditions. Good environmental control makes the difference between thriving crops and repeated failures.

Temperature targets and control

• For cool-season crops (leafy greens, brassicas): daytime 55-70 F, nighttime 40-50 F.
• For warm-season crops (tomatoes, peppers, cucurbits): daytime 70-85 F, nighttime 60-70 F.
• For seedlings and tropical herbs: consistent 65-75 F.

Use thermostats with heaters for winter, venting and shade cloth for summer. In Mississippi winters, a small propane or electric greenhouse heater with a thermostat is usually sufficient for most winters unless a hard freeze is prolonged.

Humidity and ventilation

High humidity in Mississippi promotes fungal disease. Aim for 50-70% relative humidity. Provide cross-ventilation, roof vents, exhaust fans, and circulation fans. In summer, shaded ventilation reduces heat and humidity spikes; in winter, ventilation during the warmest part of the day reduces condensation.

Light and shading

Glass or clear polycarbonate allows excellent light. In midsummer, install 30-50% shade cloth for heat- and light-sensitive crops such as lettuce and basil. Supplemental LED lighting in winter can speed growth for transplants and leafy greens.

Soil, containers, and watering

Use well-draining soilless mixes (peat or coconut coir, perlite, composted bark) in containers or raised beds to avoid waterlogged roots. Employ drip irrigation or soaker hoses to reduce humidity and leaf wetness. Fertilize with balanced soluble fertilizer; increase potassium for fruiting crops.

Pollination and pest control

Greenhouses limit natural pollinators; introduce bumblebee hives for tomatoes and cucurbits or perform hand pollination. Scout weekly for thrips, whiteflies, aphids, and fungal diseases. Use sanitation, sticky traps, and integrated pest management (beneficial insects, insecticidal soaps) rather than routine broad-spectrum sprays.

Winter (December-February): focus on cool-season greens and transplants

Mississippi winters are mild compared with the North, but greenhouse growers should treat this season as an opportunity to produce cool-season crops and to start warm-season transplants early.

Best crops to grow in winter

• Lettuce and mixed salad greens (leaf varieties like ‘Buttercrunch’, ‘Black Seeded Simpson’).
• Spinach and Swiss chard.
• Kale and collards.
• Asian greens: bok choy, tatsoi, mizuna.
• Radishes, carrots (short-rooted types), and beets.
• Peas (sugar snap and snow peas) in the early winter months.
• Herbs: parsley, cilantro, chives, thyme (watch rosemary; it prefers very good air circulation).
• Pansies and violas for ornamental sales or winter color.
• Seedlings of tomatoes, peppers, and eggplant (start late winter for spring planting).

Practical winter notes

Provide supplemental lighting if you need faster growth or denser transplants. Nighttime heating to maintain 45-55 F avoids frost damage. Maintain good air circulation to prevent Botrytis and powdery mildew. If starting tomato and pepper seedlings, keep daytime temps around 70-75 F and nighttime temps 60-65 F to avoid leggy seedlings.

Spring (March-May): early production and extended outdoor transplanting

Spring is when the greenhouse can produce early harvests of warm-season crops and harden off transplants for Mississippi’s outdoor season.

Early spring greenhouse crops

• Early tomatoes and peppers (determinate and indeterminate varieties started in late winter).
• Cucumbers and squash (start in greenhouse early, move out once nights are reliably above 55 F).
• Basil, cilantro, and Mediterranean herbs.
• Continued production of cool-season greens for continuous harvest.

Transplanting strategy

Harden off seedlings gradually over 7-14 days before transplanting outdoors. Use the greenhouse to give seedlings a head start 4-6 weeks before the average outdoor planting date for your county. In most of Mississippi, outdoor transplant dates for tomatoes and peppers fall in late March through April; in northern Mississippi expect later dates.

Summer (June-August): managing heat and growing heat-loving crops

Summer in Mississippi is hot and humid. The greenhouse must be managed to avoid heat stress and disease.

Heat management

• Use 30-70% shade cloth depending on crop and location.
• Install automatic vent openers, exhaust fans, and circulation fans.
• Consider evaporative cooling if humidity can be controlled or if venting is sufficient.

Crops that perform well in summer greenhouse conditions

• Heat-tolerant tomato varieties (look for ‘Heatmaster’, ‘Solar Fire’, or other “heat set” cultivars).
• Peppers (sweet and hot) that handle high temperatures.
• Okra (does well in containers and thrives in heat).
• Eggplant.
• Cucumbers and melons if ventilation and pollination (bumblebees or hand pollination) are provided.
• Basil and other culinary herbs (grow basil early in the morning and water the root zone to avoid foliar disease).

Disease and insect prevention in summer

High humidity fuels fungal growth and insect populations. Water in the morning, avoid overhead watering, and use integrated pest management. Frequent leaf removal to improve airflow reduces disease incidence.

Fall (September-November): second season for cool crops and overwintering

Fall is an ideal time to use the greenhouse to extend the production of cool-season vegetables and to plant brassicas for winter harvest.

Fall crop list

• Brassicas: broccoli, cauliflower, cabbage, Brussels sprouts (start in late summer in greenhouse, transplant to greenhouse beds or cold frames).
• Fall and winter greens: lettuce, spinach, kale, mustard.
• Garlic and overwintering onions (plant in fall for spring harvest).
• Root crops: late carrots and beets planted in late summer to early fall.
• Herbs: parsley and cilantro that prefer cooler weather.

Overwintering and harvest notes

Use row covers or secondary cold frames inside the greenhouse if an unexpected hard freeze threatens. Keep brassicas ventilated on mild days to prevent mildew and keep insect pressure low for cleaner heads and leaves.

Succession planting, crop rotation, and year-round planning

To keep production steady and soils healthy, plan for succession planting and rotate crop families within containers, beds, or gutters.

1. Stagger sowing dates every 2-3 weeks for greens to ensure continuous harvests.
2. Rotate legumes, nightshades, and brassicas so soils do not accumulate specific pests or pathogens.
3. Flush containers occasionally and refresh potting mix yearly for intensive greenhouse production.
4. Grow cover crops or green manures in larger beds over slow periods to rebuild organic matter and suppress pathogens.

Practical takeaways and sample month-by-month schedule

• Keep greenhouse temps in the 55-85 F range depending on crop family; provide heating to avoid prolonged exposure under 45 F for tender transplants.
• Aim for 50-70% relative humidity and actively manage ventilation and circulation.
• Use shade in summer and supplemental light in winter when you need faster growth.
• Hand-pollinate or introduce pollinators for fruiting crops.
• Scout for insects and disease weekly; prefer sanitation and biological controls over heavy insecticide use.
• Maintain a continuous planting schedule with staggered sowings and clear crop rotation plans.

Sample monthly actions for Mississippi greenhouse:

• January-February: Produce cool-season greens, start tomato and pepper seedlings, maintain minimum heat, plan spring crop layout.
• March-April: Harden off transplants, plant cucurbits and early tomatoes in greenhouse for early fruiting, continue lettuce succession plantings.
• May-June: Switch to heat management (shade cloth), plant heat-loving crops, ensure good ventilation and pollination.
• July-August: Manage humidity and disease; focus on okra, eggplant, heat-tolerant tomatoes, basil; prepare fall crop seedlings.
• September-October: Start brassicas and fall greens; reduce night temperatures gradually; plant garlic and overwinter onions.
• November-December: Harvest remaining greens and brassicas, maintain frost protection, and prepare soil and containers for winter crops.

Closing recommendations

A Mississippi greenhouse can produce fresh vegetables, herbs, and flowers throughout the year when you match crops to seasonal temperature and humidity realities. Start with an environmental control plan (heat, venting, shading), choose appropriate varieties for heat or cool tolerance, and practice strict sanitation and succession planting. With the right setup and timing, your greenhouse will deliver higher yields, earlier harvests, and a wider variety of crops than outdoor planting alone.