Protected Cultivation

Protected Cultivation of Squash

​Squash cultivation is economical during fall, early spring and single crop seasons. The appropriate drilling periods are September in Fall season, end of October and beginning of November in single crop season and middle of December in early spring season. Squash seedlings are grown in the same way as cucumber seedlings. However, as there is a considerable risk of viruses in fall season, seedlings need to be covered by a fine muslin or a mosquito net for protection against white flies. Squash plant is trellised using a string in order to save from space. Pruning is not done for squash. However, fruit flowers which are not inseminated on the plant and thus not able to grow are picked up and discarded as these are the most appropriate environments for the development of grey mould and white mould, which are serious diseases found in greenhouses. Squash does not like too much heat. 


Squash grows well in low temperatures. Even a light frost can cause death. Male and female flowers, which are on the different parts of the squash plant, need to be pollinated through insects. Therefore, unnecessary insecticides should be avoided. 

In addition, in January and February during single crop season, when the environment is not appropriate for insemination, it is possible to promote fruit set by 4 CPA hormone application with the dosage of 20 PPM to newly emerged female flowers. Squash should be harvested at the latest once in 3 three weeks in winters and once in two weeks in other seasons. Harvesting should be carried out with knife and fruits should not be harmed. In addition, during the seasons with high temperature, harvesting should be done early in the morning.

Protected Cultivation of Eggplant

​Protected farming is done for long years in our country. Protected eggplant cultivation began in 1970s. Eggplant varieties grown in greenhouses are expensive as they are hybrid eggplants. Therefore, healthy seedlings should be produced without giving any harm to the seeds. Drilling can be done either by scattering into boxes by hand under appropriate temperature or by using row planting system. After drilling, the area must be covered with compost screened to 1/5 inch particles. Plants should be kept out of sunlight as from the emergence and should be gradually adjusted. When the seed leaves fully emerge and the first real leaf is seen, it is time for transplanting. As transplanted plants are sensitive, they should be kept out of direct sunlight for 2 to 3 days. Seedling bags should be placed in such a way that there will be enough space between so that they will not touch each other. 

A good seedling growth should be allowed so that when the seedlings are ripened, flower bud will be formed with equal width and length. Plantation should be done in a cold atmosphere and reirrigation may be necessary depending on the climatic conditions. The most appropriate temperature for eggplant is 77 to 86F°. If the night temperature is below 60 F°, fruit set does not emerge. In order to provide insemination under these conditions, plant growth regulators are needed​. Development decelerates under low temperatures and plant begins to freeze at 32 F°. 

Protected Cultivation of Pepper

​Pepper is an important vegetable in that it contains high calorie value, vitamin C and mineral substances. Pepper cultivation covers a 15% area of the total greenhouse vegetable cultivation. Protected pepper cultivation is generally done in single crop and spring seasons. As tomato highly suffers from viruses in fall season, this season is appropriate for pepper growing. In our greenhouses, registered varieties or varieties with production permit as well as hybrid seeds are used. The first requirement for success in pepper cultivation is to choose the variety most appropriate for the season and then growing healthy and robust seedlings.

Sowing compost and seedling compost should be well prepared. They should be rich in nutrients and free of bacterial diseases as much as possible. After the seed is germinated, the cotyledon leaves should become large enough and when the first leaf is seen, the plants should be transplanted in compost sacks, pots or other seedling growing environments without causing any harm to the plants. Before planting the seedlings in their actual places in the greenhouse, the necessary soil preparation should be made. 

Ripe seedlings are planted in the greenhouse during the day hours except from when the weather is hot. Depending on the water need of the plant, necessary watering should be done. It is necessary to ensure that the crown root of pepper plant does not contact with the irrigation water in order to protect this plant against the crown root disease. The ripening of pepper in harvest depends on the variety and environmental conditions. Pepper should be harvested when its size is appropriate. If it is harvested too early, its tolerance to road conditions is reduced. On the other hand, harvesting pepper too late causes reduced quality.

Protected Cultivation of Cucumber

​Cucumber is one of the most important vegetables grown in greenhouses. Grower should begin with a variety appropriate for cucumber cultivation. 

As sowing is done throughout the whole year in the greenhouses, the varieties recommended for each season is different. There are also some seasons in which sowing and planting are more intensely done.


Appropriate Sowing Time for Cucumber





Early Fall


Late Fall

The first half of September

Single Crop

The second half of October

Early Spring

The second half of December


January and February

Late Spring

March-Middle of April

Protected Cultivation of Tomato

​While choosing the crops to be planted, it is important to choose the varieties which are appropriate for the growing season and have a potential of healthy growing, high productivity and long shelf-life. The appropriate sowing time for tomato changes depending on the growing environment and region. ​


Appropriate Sowing Time for Tomato










Single Crop


Middle of September

Beginning of October




End of November

Beginning of December

It is appropriate to sow tomato seeds at the end of July and beginning of August for the Fall season, in the middle of September and the first week of October for the single crop season, at the end of November and the first week of December for the Spring season. When the cotyledons leaves of tomato seedlings are wide open and parallel to the ground, they are transplanted into plastic bags or viols. Seedlings ready for plantation should be planted in double-row system from north to south. Planting measure is 45-15X20 inches for double crop growing and 40-20x15 inches for single crop growing. Seedlings which have 4 to 6 leaves are ready for plantation. In fall season, planting should be done in time when the seedling is still small. 

Fertilization should be done in accordance with the results of soil and leaf analysis. In fall season cultivation, the greenhouses should be covered with a fine muslin to protect against white flies. In single crop and spring seasons, mulch and heat curtain can be used for forcing and saving from energy. The subsoil, which is 10-15 inches under the soil, should be broken once in two or three years.

Protected Vegetable Cultivation

​Vegetable and fruit growing and ornament planting in low and high systems under environmental conditions created by eliminating external climatic factors is called protected cultivation. Among these systems, there are high constructions protected by glass or plastic, which are called greenhouses. As more crops can be harvested using protected vegetable growing than outdoor agriculture, income increases likewise. In protected vegetable cultivation, tomato growing comes first. Then comes cucumber, eggplant, melon, squash and watermelon growing. These vegetables are grown in greenhouses in three different seasons, namely fall season, single crop winter season and spring season. Different from the outdoor agriculture, protected vegetable cultivation requires some processes. One of them is mulching. Mulching means forming a protective layer of organic or inorganic materials over the soil in order to increase the quality and amount of crops.


Mulching causes heat difference of about 37 to 41°F in soil and gives way to healthy plant growing. Preventing excessive evaporation of soil surface, it decreases the number of required irrigation. Decreasing the humidity in greenhouse, it prevents the spread of some bactericidal and fungicidal diseases. It also prevents salification of the soil. Mulching increases productivity and forcing ranging from one crop variety to another. Mulching has little or no negative impacts. As it decreases the humidity in the greenhouse, it helps the spread of mildew and red spider.

Melon and watermelon grow better on sandy loam or loamy sand, deep, air permeable, nutritionally rich soils free of drainage problem. Melon roots in particular are highly sensitive to oxygen deficiency. Appropriate temperature for melon and watermelon seeds to germinate better is 77 to 86°F. Seeds which germinate under this temperature need minimum 53 to 59°F temperature to continue growing. In addition, the proportional humidity melon and watermelon require in protected cultivation phase is 70% to 80% at night and 50% to 65% during daytime. In coastal regions, melon and watermelon are grown as the second crop in protected cultivation in Spring season. Melon is commonly grown in glass and plastic greenhouses while watermelon in low plastic tunnels. Seeds, which are germinated under 77 to 86°F temperature, are planted shallowly and not too deeply in the prepared pots and plastic bags. They are lightly watered and covered by polyethylene sheet. When the first growing begins, this sheet is removed. If possible, low tunnels can be constructed over these pots or bags grown in the seedbed​.