How to grow evening primrose? The latest planting techniques and methods tutorial

Evening primrose is an upright biennial robust herbaceous plant of the genus Oenothera in the family Onagraceae, also known as late cherry primrose, evening star grass, mountain sesame, wild sesame, etc. It is native to North America, was introduced to Europe early on and then spread rapidly through the world's temperate and subtropical regions. It is cultivated in Northeast China, North China, East China and Southwest China and has long since become naturalized. Now let us take a look at evening primrose planting techniques!

Evening primrose planting environment

Evening primrose has strong adaptability, tolerates acid and drought, and is not demanding about soil. It can generally grow in neutral, slightly alkaline or slightly acidic soil, and in well-drained, loose soil. In soil that is too wet, the roots are prone to disease. In the north it is an annual plant, and south of the Huai River it is a biennial plant. It often grows on open barren slopes and roadsides, tolerates drought and poor soil, and is suitable for planting in black soil, sandy soil, loess, young forest land, lightly saline-alkali land, wasteland, river beach land and hillside land.

Evening primrose seed propagation

Evening primrose can be sown in both spring and autumn. The autumn sowing period is from mid-October to before the ground freezes. If there is heavy winter snow, autumn sowing is better than spring sowing; if there is little winter snow, it easily causes missing plants and broken rows. Spring sowing can be done before sowing wheat, when the soil has thawed 2-3 cm. Because the sowing rate is low, 60 kg of diammonium per hectare is mixed with the seed as a filler. If this is insufficient, a certain amount of dry sawdust or roasted wheat, rapeseed, etc. can be added for sowing. The sowing depth is 1-2 cm, and the soil should be pressed promptly after sowing. The seed rate is 6 kg per hectare, and the target stand is 400,000-500,000 plants per hectare. The density at sowing must not be too low, otherwise branching will occur and the maturity period will be uneven.

Evening primrose cutting technique

1. Cutting shoots and cuttings: The branches used for evening primrose cuttings are called cuttings. Usually combined with pinching work, the robust, pest- and disease-free top shoots that are pinched off are used as cuttings. The optimum temperature for cutting rooting is 18-25°C. Below 18°C, the cuttings root with difficulty and slowly; above 25°C, the cut ends of the cuttings are easily infected by pathogens and rot, and the higher the temperature, the greater the proportion of rot.

2. Temperature management: When low temperatures are encountered after cutting, the main measure for keeping warm is to wrap the flower pot or container used for cuttings with plastic film. When the temperature is too high after cutting, the main cooling measure is to shade the cuttings, blocking 50-80% of sunlight, and at the same time spray the cuttings 3-5 times a day. On sunny days with higher temperatures, spray more often; on cloudy and rainy days with lower temperatures and higher humidity, spray less often or not at all.

3. Humidity management: After cutting, the relative air humidity must be maintained at 75-85%. Humidity can be increased by spraying the cuttings 1-3 times a day. On sunny days, the higher the temperature, the more frequent the spraying; on cloudy and rainy days, the lower the temperature, the less frequent the spraying or no spraying. However, excessive spraying makes the cuttings easily infected by pathogens and rot, because many kinds of pathogens exist in water.

4. Light management: Cutting propagation cannot do without sunlight, but the stronger the light, the higher the temperature inside the cuttings, the more vigorous the transpiration of the cuttings, and the more water consumed, which is not conducive to the survival of the cuttings. Therefore, after cutting, 50-80% of sunlight must be blocked. After the root system has grown, gradually remove the shade net. On sunny days, remove the shade net at 4:00 p.m. each day and cover it again before 9:00 a.m. the next day.

Evening primrose planting techniques

1. Land selection and preparation: Evening primrose is robust by nature, tolerates cold, drought and poor soil, likes light, and avoids waterlogging. Fields with fertile soil and good drainage that previously grew beans or melons should be selected for planting. Continuous cropping is possible, but plots with residues of herbicides such as chlorsulfuron, chlorimuron-ethyl, Pursuit and Command cannot be used to grow evening primrose. For land preparation, bean stubble and mixed stubble can be directly harrowed and ridged in autumn.

2. Potting substrate: The substrate used for potting can be one of the following: vegetable garden soil + furnace slag = 3 parts + 1 part, or garden soil + medium-coarse river sand + sawdust (mushroom residue) = 4 parts + 1 part + 2 parts, or peat + perlite + ceramsite = 2 parts + 2 parts + 1 part, or vegetable garden soil + furnace slag = 3 parts + 1 part, or peat + furnace slag + ceramsite = 2 parts + 2 parts + 1 part, or sawdust + vermiculite + medium-coarse river sand = 2 parts + 2 parts + 1 part.

3. Potting seedlings: When potting seedlings, first put 2-3 cm thick coarse-grained substrate or ceramsite at the bottom of the pot as a drainage layer, sprinkle a layer of fully decomposed organic fertilizer on top as base fertilizer about 1-2 cm thick, then cover with another layer of substrate about 1-2 cm thick, and then place the plant in so that the fertilizer is separated from the root system to avoid burning the roots. After potting, water thoroughly once and keep it in a slightly shaded environment for one week.

4. Transplanting seedlings: When transplanting seedlings, first dig the planting hole, sprinkle a layer of organic fertilizer at the bottom of the planting hole as bottom fertilizer (base fertilizer) about 4-6 cm thick, then cover with a layer of soil and place the seedling in so that the fertilizer is separated from the root system to avoid burning the roots. After placing the seedling in, backfill the soil to cover the root system, press the soil firm with your foot, and water thoroughly once.

5. Field management: Before the second pair of true leaves expands, the seedlings are very similar to weed seedlings and easily confused, so intertillage weeding cannot be carried out at this time; it can only be done after the second pair of true leaves has unfolded. When the seedlings grow to 5-6 leaves and there are many grass weeds, quizalofop-p-ethyl and haloxyfop can be used for spray weeding. During the growth period, 2 rounds of hoeing and 2 times of intertillage should be carried out. The hoeing and ridging must be finished before flowering. When the seedlings cover the rows, carry out the first round of hoeing and intertillage. In late July and early August, carry out 2 times of manual pulling of large weeds so that there are no weeds in the field taller than the evening primrose plants.

6. Harvesting and processing: Evening primrose has an indefinite inflorescence, and the fruits mature successively. Generally, when 3-4 pods at the bottom turn yellow and are about to split, it is the best harvest period, specifically in mid-to-late September. If later, the early-maturing fruits will have dried and split, and the seeds will scatter on their own. Manual harvesting or swathing with a windrower can be used. After drying for 5-7 days, use a combine harvester to pick up the grain or thresh manually. After harvest, the seeds are graded and cleaned with a grain cleaning machine to remove impurities. After drying, when the moisture content drops below 11%, bag them for storage or sale.