It is not a surprise that strawberries are one of the most popular fruits around the world. Their mouth-watering sweet taste is refreshing and they provide a lot of good nutrition. Who wouldn’t like to grow them in their garden?! The growing season, however, is quite short. That’s why it is a good decision to grow strawberries in a greenhouse in order to have a fresh home-grown supply of these wonderful berries all year round.
Strawberry science facts
Garden strawberries grown today are a hybrid of species of the genus Fragaria. This plant that is cultivated worldwide is famous for its sweet fruits that have a characteristic aroma, juicy texture, and attractive red color. People all over the world consume strawberries in large quantities either as fresh fruits or in processed foods such as fruit juice, milkshakes, ice cream, cakes, or chocolates. Check out these recipes!
Strawberries are one of the most in-demand fruit because of its all-year-round availability. There are roughly 1800 acres of strawberries that are being harvested in North Carolina alone. And almost all of them are raised in the coastal environments of California.
Scientists are experimenting with the assembled genome which will let them identify special genes that can protect these berries against diseases like Verticillium and Fusarium wilt and Macrophomina. It will also enhance the taste or aroma and prolong its shelf life. Strawberries carry eight comprehensive sets of chromosomes in every cell, that is why solving its growth is an accomplishment.
Types of strawberries
Depending on your needs and goals, you should know that there are different types of plants to choose from. Even if you grow strawberries in a greenhouse, it will not change the bearing times of the plants much. Therefore, picking the right type of plant is crucial for your year-round strawberry supply. If you just want to extend the picking season, you still may use seasonal plant types.
June bearers are amazingly common and affordable. They provide the highest strawberry yields and you can normally achieve it over a span of two to three weeks. They are divided into Early Season, Midseason, and Late Season.
Early Season strawberries normally start fruiting in the late spring. Early Midseason strawberries start fruiting around five days after Early Season varieties. Midseason strawberries start bearing fruits nearly eight days after Early Season varieties. Late Midseason strawberries will start fruiting in about ten days after Early Season varieties. Late Season strawberries will produce their berries approximately 14 days after the Early Season varieties.
Everbearing strawberries do not bear fruits endlessly. They usually allow two harvests every year. It is also likely for some of them to produce three harvests under excellent conditions. They put out fewer runners than the June bearing varieties. They are set using the hill system or in areas where space is short.
Day-neutral strawberries are unique. They will produce a healthy harvest in the first year. They flower and fruit as long as the temperature is between 35°F to 85°F. Outside they can bear fruits from April until October. A greenhouse, however, can provide the perfect conditions for them to give you a year-round supply. The disadvantage of this variety is that they produce smaller berries than June-bearing and everbearing strawberries. These berries are also planted using the hill system just like the everbearing ones.
Strawberry runners are also called stolons. They are parallel stems that spread above the ground and create brand-new clone plants at nodes spaced with alternating intervals. This is the reason why strawberries are recognized as stoloniferous. The long and leafless stems between the mother plant, the plant-growing nodes, and the growing point of the stolon are called internodes.
Adventitious roots give strawberries an advantage over other plants. Strawberries are capable of propagating themselves through runners. This lets them discover better soil or spots with sufficient sunlight. Since strawberries never stop sending out runners, their beds have to be constantly thinned in order to maintain a healthy production.
How to grow strawberries in a greenhouse
Sun-ripened strawberries are easy to grow in any greenhouse if you follow the guide below.
- Get disease-free seedlings from reputable nurseries
- Plant them into the ground, pots, planters, or raised beds
- Ensure the hole is deep enough to accommodate the whole root system without bending them and make sure the crown remains just above the surface.
- Work the soil in raised beds as this offers the best condition for greenhouse-grown strawberry. Then mulch the beds to regulate water loss and minimize the invasion of weeds.
- Don’t plant your strawberries too deep because they might rot.
- For easy passage, it is helpful to provide your strawberries with plenty of areas. Use a trowel to bore a hole large enough to accommodate the roots, and if you are planting in the ground, plant them 18 inches apart, leaving 30 inches between rows.
- If you are planting runners, lay the roots out in the slot and make sure that the crown is resting at soil level. The same works for planting in pots.
- The pots should be at least six inches in diameter with several draining holes.
- For a 12in wide hanging baskets, three to four strawberry plants are enough. Florian variety is the best choice for hanging baskets because it bears fruit both on the mother plant and its runners. Use Plant Caddie Hooks for your hanging baskets - They make it easier to raise and lower the basket for care and harvest!
- If you start off immature plants or tendrils in a greenhouse, plant them in a clear pouch or humid propagator till the roots have settled.
- Apply a water-soluble organic compost that has high potash amount to promote fruiting.
- Planting from seed takes a small dose of patience because they can take up to a month to sprout and will normally crop the next year.
Tips & tricks
- When the flowers bloom, fill them with an organic liquid fertilizer every fortnight.
- Other variations of strawberry produce runners or stem with blooming plants along the length. Eliminate them when they appear so that the plant’s vitality will go towards fruiting and flowering.
- If you planted the June-bearing berries, remove the flowers on its first year so that you can have a rich harvest in June.
- The VegiBee Garden Rechargeable Pollinator will be helpful to encourage fruiting. Some berries can become deformed due to non-pollination.
- You can also grow sweet strawberries from pots.
- Straws and fiber mats keep down weeds and prevent root rot.
- Crop rotation is still the best practice. Replace your strawberry plants after three years.
- It will create a green color on the underside of the fruit is there is an oversupply of nitrogen so be careful with it.
A year-round supply of strawberries
As mentioned earlier in this post, you can achieve a year-round yield of strawberries by picking the right plant type. Proving the right conditions for your strawberry plants forces them into bearing fruits for longer periods.
There are simple ways of forcing strawberries so that they can flower and fruit earlier, later, or multiple times a year:
- Choose different types of strawberry plants to have a year-round harvest. For example, get 10 everbearing, 5 June-bearing, and 10 day-neutral plants. This way you will have different plants bearing fruits at different times of the year. Of course, you will have to choose the number of plants you need for your preferences.
- In order to make strawberry plants flower, they need a good chill. So, you should plant them in pots which you can easily move in and out the greenhouse. This way you can give them the break they need.
- Choose a pot that is around 12 to 15 inches deep and well drained. Terra-cotta or plastic pots with cup-shaped holes throughout the sides are good.
- Pollination can be a problem especially in the colder months but a VegiBee Pollinator can help you all the way. Strawberries are short-lived plants so after forcing, you need to discard and replace them.
Raising strawberries in a greenhouse prevents them from pests and outside weather and it means that they will fruit up to a month ahead than outdoor.
Please, keep reading below for providing the best growing conditions.
Because of the shallow roots, strawberries thrive when the ground is wet. They need frequent watering in hot summer days. But they don't like sitting in the water-logged ground, which can weaken the crown and cause the berry to rot.
It is reasonable to water from the base. Ideally, provide about an inch and half of water each week. It is better to water early in the morning so that the water will not dry out fast. Take a look at these Greenhouse Irrigation System for excellent ground watering!
Strawberries do well in nutrient-rich, well-drained, acidic soils that have high concentrations of organic matter. You can fertilize your strawberries twice a month with a well-balanced, organic compost throughout the growing period. The optimal pH should range between 5.5 and 7.0. Combine a layer of straw or mulch throughout the surface to keep the roots cold and free from moisture. Switch to a high-potash liquid fertilizer right after they start to bloom. This will maximize its fruit-bearing ability.
Make sure that the glazing of your greenhouse is clear and there is nothing in the way to obstruct out the light. They must receive at least six hours of daylight every day, some varieties need up to 12 hours. As such, choose your greenhouse site appropriately and ensure the greenhouse kits you buy allow adequate light. With lessened light and photosynthetic movement, they cannot bear many fruits.
If you want to grow strawberries in winter, you should use a grow light to give your plants enough daylight. Otherwise, they will not develop many fruits. Read this article in order to pick the right Grow Light!
Strawberries love to flower in a cool to warm weather. The temperature must not go over 77ºF because higher temperatures can negatively impair the growth and kill the pollens. Keep the greenhouse temperature around 65-77°F until they start flowering. Once you have picked the strawberries, decrease the temperature inside your greenhouse so that it stays cold throughout winter. A cool phase is important to stimulate them to flower the next season. This only matters if you choose June-bearing or everbearing strawberry plants.
In the first eight months or so, pick off the blossoming flowers so the strawberry plants do not fruit. If you want to start growing strawberries from runners, make sure to maintain proper humidity levels because runners are usually more sensitive to warm temperature than grown berries.
Common problems, pests, and diseases
Strawberries are susceptible to several common problems such as garden pests. Some of these are Japanese beetles, spider mites, slugs, and snails. Diseases such as powdery mildew and gray mold may cause serious losses as well.
Maintain greenhouse cleanliness and be observant for manifestations of disease to prevent them from spreading. Remove those dead foliage because they can harbor pests and diseases over the wintertime.
Make sure that your strawberries won’t be attacked by the verticillium wilt. Order certified classes and don’t plant them close to another plant like eggplants and tomatoes. You can prevent and reduce further threats by maintaining a neat greenhouse. Get rid of all dead plants before they decay.
It is suitable to substitute strawberry plants after the third season or they may lose vigor producing lesser harvests, and your berries will become more susceptible to pests. If your space permits, move the beds to another section to prevent pests and diseases from growing.
Red stele root rot is caused by Phytophthora fragariae. It is one of the severe fungus diseases of strawberries in the U.S. This organism invade plants throughout winter until springtime. It is very harmful in heavy clay soils soaked with water.
Ingredients for a basic fungal disease treatment
- Two drops of organic olive oil
- Two drops of liquid detergent
- Three tablespoons of baking soda
- One gallon of water
Strawberry fruits are usually ready about five weeks after the flowers blossom. Harvest by picking them every two days. Remove the mulch when the last strawberries have been harvested. Do not pull just pinch or cut them, leaving a half inch of stalk.
Remove excessive immature fruits to keep your harvest time longer. If the plant bears a lot of fruits at once, it will transport its nourishment to fruits. Then the plant itself will get weaker.
Indulgence is acceptable when it comes to strawberries. Harvest them quickly as they ripen or they will rot on the plant. Monitor them every other day throughout the ripening season.