From Longman Dictionary of Contemporary Englishplant something ↔ out phrasal verbGROW PLANTS, VEGETABLES ETCto put a young plant into the soil outdoors, so that it has enough room to grow The seedlings should be planted out in May. → plant→ See Verb table
Examples from the Corpus
plant out• They include oleander, poinsettia and other members of the Euphorbia family, and the castor-oil plant.• Here at this private works in Newnham, the reed plants filter out all the impurities in the waste.• Symptoms will start to show shortly - affected plants stand out as more upright types, with erect and narrow leaf stalks.• Give them a slightly acid compost, and don't allow the plants to dry out at all.• For that reason tropical plants usually put out flower buds and flower by slow growth one to three months later.• But sometimes they used lashings of rattan, a jungle plant which threw out long tendrils that made natural bindings.• The substrate may be richer than usual for the genus because this plant grows out of the water.• This latter proposition is not ideal as the more rampant plants will crowd out the less vigorous and often more desirable subjects. 