In The Greenhouse This March

Clean the Greenhouse 

• Spring cleaning: Clean your greenhouse thoroughly to remove any winter debris, pests, or diseases. Wipe down surfaces, windows, and shelving to let in as much light as possible. Wash your pots, tools, and seed trays to prevent the spread of pathogens. 
• Disinfect: Consider using a mild disinfectant to clean surfaces. This helps reduce the risk of fungal infections and pests once you start planting. 

Ventilate the Greenhouse 

• Increase ventilation: As the weather warms, open the vents and doors of your greenhouse to improve airflow. This will help regulate temperature and humidity, preventing mold, mildew, and fungal diseases. However, if there’s a frost risk, make sure to close them overnight. 

Maintain Temperature 

• Keep the greenhouse warm: March can still bring chilly nights, so consider using a heater to keep the greenhouse at a stable temperature (usually around 5°C at night). Ensure your plants aren’t exposed to frost, as it can damage young seedlings. 
• Thermometers and thermostats: Use a thermometer to monitor the temperature and a thermostat to regulate it if necessary. The temperature should be around 18-20°C during the day and 5-10°C at night for optimal seedling growth. 

Prepare the Soil and Compost 

• Prepare planting beds: If you have raised beds or borders in the greenhouse, get the soil ready by loosening it and adding fresh compost or well-rotted manure. This will improve drainage and nutrient content for your plants. 
• Compost bins: If you’ve been collecting compost over the winter, start turning the compost in your bin to promote decomposition. 

Prune Overwintered Plants 

• Prune fruiting plants: If you have fruit trees or bushes in the greenhouse, such as citrus or figs, prune them to encourage new growth and improve air circulation. Remove any dead or damaged branches. 
• Remove dead growth: For overwintered plants, trim off any dead leaves or stems to make way for fresh growth. 

Check for Pests 

• Inspect for pests: Check your greenhouse regularly for pests like aphids, whiteflies, or red spider mites. These pests can multiply quickly in the warm conditions of the greenhouse. Use natural solutions such as neem oil, insecticidal soap, or even biological controls like ladybugs. 
• Sticky traps: Consider using yellow sticky traps to catch flying insects such as whiteflies. 

Hardening Off 

• Hardening off plants: As you start growing seedlings in the greenhouse, it’s important to gradually acclimatise them to outdoor conditions. This process is known as hardening off. Start by placing them outside for a few hours a day in a sheltered spot, and gradually increase the time over the next few weeks. 

Watering 

• Water carefully: The warmer temperatures in the greenhouse will require regular watering, but be careful not to overwater your plants. Water the base of plants early in the day to reduce the risk of fungal diseases. 
• Check moisture levels: Use a moisture meter or your finger to check soil moisture levels before watering, especially if you’re growing in pots. Overwatering can lead to root rot, so allow the soil to dry slightly between watering. 

Support Climbing Plants 

• Trellises and supports: As climbing plants like tomatoes, cucumbers, and beans start growing, make sure you have the necessary supports in place. Install trellises, cages, or string to help plants grow vertically and keep them off the ground. 

By following these tips, your greenhouse will be set up for a successful growing season, with healthy seedlings and productive plants. Happy gardening! 🌱