How to Grow Cucumbers

Types
Cucumbers come in two main types: vining cucumbers and bush cucumbers. Vining cucumbers grow up and out and benefit from a trellis or other support to keep their vines off the ground. Bush cucumbers form a more compact plant and are more suitable for containers. Vining varieties tend to be more prolific but require space to spread, while bush varieties are a good choice for small gardens.

Growing Conditions
Cucumbers require full sun, rich soil, and warm weather. Choose a location with light, well-draining soil that receives a minimum of six hours of sun per day. Prepare your soil for planting by amending with organic matter like compost, worm castings, and kelp meal.

Starting
Start your cucumber seeds 4-6 weeks before the last frost. Seeds typically germinate in 7-10 days. To speed up germination time, use a heat mat to keep your soil warm (21°C). Once your seeds have sprouted, keep them in a warm, bright location such as a south-facing windowsill or under grow lights. Check soil moisture regularly and water as needed. When seedlings produce two sets of true leaves, they may be transplanted up into 4" pots. Ensure your seedlings receive enough light or they will become thin and leggy. If needed they can be fertilized with a diluted fertilizer, and may need to be potted up again before it is time to transplant them out.

Cucumber seedlings must be hardened off before they are transplanted outside. Start on a mild day and place your seedlings outside for about an hour, then bring them back in for the rest of the day. Increase the amount of time they spend outside each day until they're ready to move outside permanently. For the first week, keep seedlings out of direct sunlight and strong wind and don't move them outside if the weather is harsh. When the seedlings are ready and the risk of frost has passed they may be transplanted into the garden. When spacing your cucumber plants, consider their mature size to allow for proper airflow between plants. If using a trellis, place it before transplanting your seedlings.

Cucumbers may also be direct sown in the garden in warmer climates after the soil has warmed to 21°C. They are very susceptible to cold damage and should not be planted out when the risk of frost remains. 

Find our full guide to seed starting here.

Cucumbers

Care
Cucumbers should be planted in a full sun area with well-draining soil. Water well after transplanting and feed with a fertilizer that encourages blooms. Cucumbers will benefit from regular feeding and can be fertilized every 3 weeks. Avoid using fertilizers too high in nitrogen which will encourage green leafy growth but no flowers or fruit. Water regularly and deeply as needed depending on the weather in your region. Cucumbers require consistent watering for the best tasting fruits, typically 1" per week. Mulch can be added around the base of each plant to help retain water in the soil.

Some cucumbers are self-fertile, while others require two plants to set fruit. Check your seed packets for specific variety information, especially when choosing seeds for small garden spaces. 

Pests and Diseases
Aphids - Small green, black, or brown insects that feed on the sap of garden plants. You'll find them under leaves, at blossom tips, and in the joints of stems.
Cucumber Beetles - Black and yellow striped beetles that eat tender leaves, creating large holes between leaf veins.
Blossom End Rot - A calcium deficiency often caused by inconsistent watering that causes dark spots on the blossom end of fruit. 
Mosaic Virus - A virus that causes mottled light and dark spots on leaves and stunted growth.
Powdery Mildew - White mildew on the top surfaces of leaves, starting as small spots and growing to cover the entire leaf.

Crop rotation, garden cleaning, and proper spacing between plants are the best ways to prevent problems caused by pests and diseases. Diatomaceous earth can be used to control crawling pest species, while sticky traps will catch flying pests. Row covers and insect netting can also prevent travelling pests from landing on your crops and causing damage. Ensure good drainage in your chosen planting spot to prevent problems with fungus and rot. Contact us for more specialized pest control methods such as beneficial nematodes. 

Harvest
It takes between 40-60 days for cucumbers to reach maturity, depending on the variety. Pick your cucumbers before they grow too large for the best flavour. Fruit should be uniformly green and crisp. During peak season cucumber plants will produce heavily, so pick them often to encourage more growth. 

Harvest your cucumbers by cutting them off of the plant with a clean pair of pruners. Cucumbers can be stored in the fridge for a week or so.