Borage or the Starflower, from the vivid blue star-shaped flowers it produces in the midsummer, is a shrub in the family Boraginaceae. These are a group of flowering plants native to the Mediterranean region and Central Europe. Its leaves and stems are covered with fine albeit bristly hairs. The plant has numerous culinary uses especially since its flowers, leaves and even stems are edible. The herb is easy to grow in a greenhouse following the guideline outlined below.
- Start the borage seeds approximately two weeks before the last frost. Plant the seeds in groups of three or four, about half an inch into the soil with a spacing of 15 inches between each group of seeds.
- Borage seeds normally germinate 5 to 10 days after sowing. The best temperature for germination is 70 degrees Fahrenheit.
- Two weeks after germination or when the seedlings attain a height of 2 inches, thin them to remain with a single plant in each hole.
Tips and tricks
The herb does not transplant well so always sow it where you want to grow it.
Borage is hardy and rarely goes under due to attacks by pests or diseases. However, Japanese beetles, wheat bugs, aphids, and springtails can be detrimental.
Borage excels in grounds that are consistently wet. Water the plants frequently and, mulch if you are located in a dry location to minimize water loss. Ideally, provide at least three inches of water weekly.
The plant thrives in almost all types of soil but the soil needs to be loose and well-aerated. Ideally, the soil should be rich, light and moist with pH ranging between 6.3 and 6.8.
Borage grows well under full sun but can tolerate a reasonable amount of shade. Greenhouse kits that come with fluorescent plant grow lights are therefore ideal for growing borage.
You can harvest the flowers when they are fully open but still fresh while the leaves can be picked at any time and used while fresh.