Whether you’re looking for an early harvest or the ability to plant potatoes any time of the year without the fear of frost, greenhouse gardening is the answer. Yes, you can grow potatoes in a greenhouse and enjoy a year-round supply in your pantry! You can grow them in raised beds, grow bags, or large containers, give them the right conditions and voilà! You’ll have a beautiful potato crop in no time!
Growing out-of-season potatoes is easy in a greenhouse. Just follow the steps, and you’ll have nothing to worry about.
What To Plant The Potatoes In?
Before planting the potatoes, it’s essential to decide what you’ll plant it in. If you don’t have the space to plant it in raised beds, you can easily go for large containers or grow bags.
Planting in beds
Planting in beds inside a greenhouse is exactly the same as you would in an open field. Fill the beds with a good quality potting mix, rich in organic matter. Cover the soil with organic fertilizer. Chitting is an excellent option to sprout potato plants before planting them in the soil.
Choose a container that’s at least 24 inches in depth and 18 inches in diameter. Make sure it has a drainage hole at the base. Cover the hole with rocks and then fill it with potting mix.
Using flexible grow bags is an excellent option for growing potatoes. It allows tubers to grow freely to the right size, without any stiff walls blocking them or distorting their shape. Many varieties are available, including plastic bags and fabric bags. The best option is to use non-degradable fabric bags since they’re porous, unlike polythene bags, and allow air circulation. Also, since they’re non-degradable, you can reuse them next season.
Preparing Seed Potatoes
The next step is to plant your potatoes in the medium you have already prepared. The most common approach is to start with seed potatoes. Simply put, seed potatoes are potatoes that are growing white shoots. You’ll most probably find a couple of these in your pantry. Choose the ones that have bulging buds. Make sure there’s no sign of rotting.
If you have large seed potatoes, you can cut them into smaller pieces, making sure there’s at least one bud on each piece. Give the cut pieces 24 hours to harden before sowing them. Many gardeners allow sprouting of the tubers before sowing them in soil.
How To Grow Potatoes In A Greenhouse
Its best to grow potatoes in containers in greenhouses. Growing in containers gives you the flexibility to move them around as well as allowing the ground to recover from the summers growth.
In a container that’s 24 inches deep and 18 inches wide, you can plant three seed potatoes. A one-gallon grow bag has room for a single tuber, while you can plant two to three tubers in a five-gallon bag. In a raised bed, plant tubers at least 12 inches apart. Make sure the buds are facing upwards and cover them with 3 inches of soil.
Set Your Container In A Greenhouse
Set the pots or containers in a warm part of the greenhouse and water them. Make sure there’s no frost in the greenhouse since it can kill your plant almost instantly.
Hilling potatoes helps increase the yield and also keeps the potatoes covered, and protected from sunlight. Green potatoes are poisonous and need to be avoided.
Start hilling, once the plant grows to about 8 inches tall. Cover it with soil, leaving the top inch open for sunlight. Repeat each time the plant grows 4 inches above the soil surface. Stop hilling once the soil reaches about an inch below the top of the bag or container.
Caring For Potato Plants In A Greenhouse
There are certain things that you need to be careful about when growing your potatoes in a greenhouse.
- If the weather is going to fall below freezing temperatures, there are two things you can do. Either use a frost cover over the greenhouse or heat the space to a suitable temperature for the plants.
- Be careful not to overwater your plants, or the potatoes will decompose. However, regular watering is required once the plants start flowering.
- After a couple of weeks since planting, start fertilizing lightly with a high-phosphorous fertilizing mix. Fertilize every week.
- Pests aren’t much of a concern when growing potatoes in a greenhouse. But you do need to watch out for beetles. If you notice any tiny eggs on the leaves, pinch them out and burn them. Act fast and use organic pesticides to get rid of them before they ruin the plant and spread to neighboring ones.
When flowers start forming, that’s an indication that tubers have formed inside the soil waiting to be harvested. Remove some of the soil to see if the potatoes are ready for harvest.
Stop watering the plants in your greenhouse a week before you plan on harvesting the potatoes. This will make sure that the soil is dry enough to allow harvesting dry potatoes. If you harvest potatoes from wet soil, you’ll have to leave them in the greenhouse until they are completely dry before storing them. Don’t use any sharp tools for digging or they may puncture the potatoes.
If you’ve grown them in a pot or grow bags inside your greenhouse, you can simply empty the contents and collect the potatoes. Even if you want to leave some of the potatoes in the soil to allow them to turn bigger in size, don’t wait too long after the plants die, or the tubers will start to rot.
Growing potatoes in a greenhouse is much simpler than growing them in an outdoor garden. Not only are your plants safe from cold weather outside, but they are also well protected against pests and diseases. Above all, you can plant multiple crops every year, without bothering yourself with the weather changes outside.