Sweet Alyssum Planting Methods and Care Tips Explained in Detail
Sweet alyssum (scientific name: Lobularia maritima (Linn.) Desv.) is a perennial herbaceous plant of the genus Lobularia in the Brassicaceae family. Its base becomes woody, and it can reach a height of 40 cm. The whole plant is covered with silvery-gray "T"-shaped hairs. The stems branch upward from the base, and the leaves are linear or lanceolate, tapering at both ends, with entire margins. The inflorescence is corymbose, the pedicels are thread-like, the sepals are oblong-ovate, and the inner ones are narrowly elliptic or narrowly ovate-oblong; the petals are pale purple or white, oblong, with bluntly rounded tips. The silicles are elliptic, the valves flattened and slightly swollen, and the tips of the pedicels curve upward.
Cultivation Techniques
1. Substrate: For potting sweet alyssum, one of the following substrates can be used: garden soil: cinder = 3:1, or garden soil: medium-coarse river sand: sawdust (mushroom residue) = 4:1:2, or one of paddy soil, pond mud, or leaf mold, or peat: perlite: ceramsite = 2:2:1, or peat: cinder: ceramsite = 2:2:1, or sawdust: vermiculite: medium-coarse river sand = 2:2:1. After potting, water thoroughly once and keep it in a slightly shaded environment for one week.
2. Potting: When potting sweet alyssum seedlings, first place a 2-2 cm thick layer of 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 a base fertilizer, about 1-2 cm thick, then cover with a layer of substrate about 1-2 cm thick, and then place the plant in, so as to separate the fertilizer from the roots and avoid burning the roots.
3. Transplanting: When transplanting sweet alyssum seedlings, first dig the planting hole, sprinkle a layer of organic fertilizer at the bottom of the planting hole as a base fertilizer, about 4-6 cm thick, then cover with a layer of soil and place the seedling in, so as to separate the fertilizer from the roots and avoid burning the roots. After placing the seedling in, backfill the soil to cover the roots, firm the soil with your feet, and water thoroughly once.
Planting Methods
Because it is relatively afraid of heat throughout the growing period, and the optimal sowing temperature is 15-20°C, autumn sowing is usually carried out after mid-to-late September: Substrate disinfection: Disinfect the substrate used for sowing. The best method is to heat it in a pot, which will scald all pests and diseases to death.
[Germination promotion]: Soak the seeds in warm water (about the same temperature as face-washing water) for 12-24 hours, until the seeds absorb water and swell. For very common seeds that germinate easily, this step can be skipped.
[Sowing]: Propagate by sowing or cuttings. For sowing, autumn sowing is preferable, as seedlings emerge quickly and evenly. The optimal germination temperature is 20°C. Scatter the seeds on loose sandy loam, press lightly, water to maintain moisture, and seedlings will emerge in 5-10 days. Transplant into pots when there are 3-4 true leaves. For potted culture soil, it is best to pre-apply a small amount of decomposed compost or phosphorus and potassium fertilizer.
For tiny seeds that are difficult to pick up with hands or other tools, you can moisten one end of a toothpick with water and stick the seeds one by one onto the surface of the substrate, cover with 1 cm of substrate, then place the sowing pot into water with a depth of 1/2 to 2/3 of the pot height, allowing the water to slowly soak up (this method is called the "pot immersion method");
For larger seeds that can be picked up with hands or other tools, place the seeds directly into the substrate and sow them at a spacing of 3 x 3 cm. After sowing, cover with substrate to a thickness of 2-3 times the seed size. After sowing, use a sprayer or fine-holed watering can to moisten the sowing substrate. Later, when the potting soil is slightly dry, water again. Still be careful not to water too forcefully, so as not to wash the seeds away.
[Management after sowing]: After autumn sowing, when encountering a cold wave with low temperatures, you can wrap the pot with plastic film to help keep it warm and moist; after the seedlings emerge, promptly remove the film, and let the seedlings receive sunlight before 9:30 every morning or after 3:30 in the afternoon, otherwise the seedlings will grow very weak; after most of the seeds have emerged, appropriate thinning is needed: pull out the diseased and unhealthy seedlings so that the remaining seedlings have some space between them; when most of the seedlings have grown 3 or more leaves, they can be transplanted into pots.
[Cutting substrate]: This refers to nutrient soil, river sand, peat soil, and other materials used for cuttings. For home cuttings, it is difficult to obtain an ideal cutting substrate due to limited conditions. It is recommended to use a pre-mixed and sterilized cutting substrate; medium-coarse river sand can also be used, but it should be rinsed several times with clean water before use. Do not use sea sand or river sand from saline-alkali areas, as they are not suitable for the growth of ornamental plants.
[Selection of cutting branches]: The branches used for cuttings are called cuttings. Usually, in combination with pinching, the thick, pest-free and disease-free top shoots that are removed are used as cuttings, and the top shoots are used directly for cuttings.
Management Methods
[Temperature]: The optimal temperature for cutting rooting is 18°C-25°C. Below 18°C, the cuttings root with difficulty and slowly; above 25°C, the cut ends of the cuttings are susceptible to infection by pathogens and rot, and the higher the temperature, the greater the proportion of rot. When encountering low temperatures after cutting, the main measure for keeping warm is to wrap the pot or container used for cuttings with 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 or not at all.
[Humidity]: After cutting, the relative humidity of the air 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 frequently you spray; on cloudy and rainy days, the lower the temperature, the less frequently you spray or you do not spray. However, excessive spraying can cause the cuttings to be infected by pathogens and rot, because many kinds of pathogens exist in water.
[Light]: 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 they consume, which is not conducive to the survival of the cuttings. Therefore, after cutting, 50-80% of sunlight must be blocked. After the root system grows out, gradually remove the shade net: on sunny days, remove the shade net at 4:00 every afternoon and put it back before 9:00 the next morning.
[Potting or transplanting]: When potting seedlings, first place a 2-2 cm thick layer of 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 a base fertilizer, about 1-2 cm thick, then cover with a layer of substrate about 1-2 cm thick, and then place the plant in, so as to separate the fertilizer from the roots and avoid burning the roots.
For the potting substrate, one of the following can be used. Garden soil: cinder = 3:1; or garden soil: medium-coarse river sand: sawdust (mushroom residue) = 4:1:2; or one of paddy soil, pond mud, or leaf mold. Or peat + perlite + ceramsite = 2 parts + 2 parts + 1 part; garden soil + cinder = 3 parts + 1 part; peat + cinder + ceramsite = 2 parts + 2 parts + 1 part; sawdust + vermiculite + medium-coarse river sand = 2 parts + 2 parts + 1 part. After potting, water thoroughly once and keep it in a slightly shaded environment for one week.
When transplanting seedlings, first dig the planting hole, sprinkle a layer of organic fertilizer at the bottom of the planting hole as a base fertilizer, about 4-6 cm thick, then cover with a layer of soil and place the seedling in, so as to separate the fertilizer from the roots and avoid burning the roots. After placing the seedling in, backfill the soil to cover the roots, firm the soil with your feet, and water thoroughly once.
[Pinching]: Before flowering, generally pinch twice to promote the sprouting of more flowering branches: one to two weeks after potting, or when the seedlings are 6-10 cm tall and have six or more leaves, remove the top shoots, keeping the lower 3-4 leaves, to encourage branching. Three to five weeks after the first pinching, or when the side branches grow to 6-8 cm long, carry out the second pinching, that is, remove the top shoots of the side branches, keeping the 4 leaves below the side branches. After two pinchings, the plant shape will be more ideal and the number of flowers will also be greater.
Cultivation management: Sweet alyssum is vigorous and can withstand mild frost, so it should be protected when overwintering outdoors; it dislikes heat and likes sunlight, and has no strict requirements for soil, but well-drained soil is preferable, and it must not be too wet. Carry out heavy pruning before the hot summer and place it in a cool spot to pass the summer, then it will bloom even more abundantly after autumn. Generally after flowering, the lower part of the inflorescence has become bare, so you can cut the inflorescence from the stem in combination with seed collection, so that new flower spikes regenerate. Slightly dry the cut parts, shake off the seeds, and store them. If the plant feels old and declining, it can also be renewed by heavy pruning, with a little liquid fertilizer applied, and soon the branches will be full of flowers again. Sweet alyssum has a long flowering period, and timely fertilization and watering should be carried out, applying dilute liquid fertilizer once every half month. Pay attention to intertillage, weeding, and pest and disease control. For potted plants, gradually switch to larger pots as the plant grows, and finally move it into a 15 cm diameter clay pot. For those overwintering in a sunny cold frame, cover with straw curtains at night to protect against cold, and move them to flower beds when spring warms up.
Cultivation method: The substrate is best peat + perlite, or leaf mold can also be used. Sieve the culture soil and place it in a seedling tray, soak it thoroughly with 500-600 times carbendazim solution, and after it dries slightly, sow by dibbling or broadcasting, about 1000 seeds per square meter. Spray with the medicinal solution to help the seeds contact the substrate closely. Cover with film or glass, and provide shade and moisture. Seedlings emerge in about 8 days. After emergence, gradually remove the film and gradually increase light. Use 1000 times chlorothalonil or thiophanate-methyl once a week to prevent damping-off, for 2-3 consecutive times.
2-3 weeks after sowing, when there are 4-5 true leaves, they can be planted in 13 cm pots, with 1-3 plants per pot. After one week, carry out normal water and fertilizer management, applying a compound fertilizer solution once a month (150PPM, equivalent to 1.5 grams of fertilizer in 10 kg of water), and adding dilute organic fertilizer solution with each watering. After 10 leaves, the fertilizer concentration can be increased to 1000PPM (1 gram of fertilizer in 1 kg of water). Do not let fertilizer water touch the stems and leaves. Do not leave them in long-term rain during the plum rain season. Moisture or poor drainage easily causes root rot. If the weather suddenly turns hot, temporarily move the potted flowers to a ventilated and cool place, which can prolong the flowering period and lifespan.