When to sow borage?
- Botanical name
- Borago officinalis
- Family
- Boraginaceae
Borage is sown from April to May. It flowers from May to September.
Borage is an annual plant. The edible parts are the leaves and flowers.
It is sown straight into the place where it will grow. It flowers until a harder frost brings the plant down. After the first year the sowing is not repeated, because borage seeds itself. The seed overwinters in the bed and germinates in spring, and the seedlings take a light frost.
The leaves contain pyrrolizidine alkaloids, which build up in the body and in larger amounts damage the liver and the lungs. Only a few of them go into a salad or a tea.
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Borage through the year
- sowing
- flowering
In short
Growing conditions
Is borage toxic to cats and dogs?
In larger amounts, toxic to people and animals, toxic parts: leaves.
Companions in the bed
Companion planting is tradition and not an agronomic claim. What is recorded is which pairs sources recommend and which they advise against.
Borage at the edge of the bed is forage for the pollinators. It seeds itself on, so leave it the edge and not the middle.
Borage at the edge of the bed is forage for the pollinators. It seeds itself on, so leave it the edge and not the middle.
- “Cited” means the pair is named by one source or two.
Pests and diseases
Listed here is every problem for which the sources name this plant as a host. The problems are not listed in order of how common they are.
- Signs
- A white, floury coating spreads over the leaves, first on the lower and older ones. The leaf under it yellows and dries up. The fruit stays small, because the plant loses leaf surface.
- Prevention
- Plant resistant varieties, leave an airy spacing and sun, and clear the debris at the end of the season. Unlike most fungi it is not helped by wet foliage, since it spreads in heat and high air humidity, in a dry summer too.
- What to do
- Oil products meant for powdery mildew on the squash family work on contact. They do not cure a leaf that is already affected, but they stop the spread to healthy ones. On herbs cut the affected shoots back instead, since the new growth comes clean. On ornamental perennials what is left is spacing and moisture.
Check the registration and the label before use.
Keep track of your plants with Tendask
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Sources about the plant: ASPCA Toxic and Non-Toxic Plants, Clemson Cooperative Extension, GBIF Backbone Taxonomy, NC State Extension Plant Toolbox, Royal Horticultural Society, Utah State University Extension, Wikidata. Checked between 14 and 28 August 2026. The problem descriptions also draw on: KGZS, UF/IFAS Extension, University of Maryland Extension, University of Wisconsin-Madison Division of Extension.