The Collaborative International Dictionary
Underplant \Un`der*plant"\, v. t. [imp. & p. p. Underplanted; p. pr. & vb. n. Underplanting.] To plant under; specif. (Forestry), to plant (young trees) under an existing stand.
Wiktionary
n. A plant that has been planted underneath others. vb. (context transitive English) To plant underneath.
Usage examples of "underplant".
The sides of the building were framed by immaculately trimmed yew and beech hedges that led to groves of coppiced trees underplanted with carpets of fresh white cyclamen.
In front of the house was a neatly tended square lawn which had been underplanted with crocuses, now just past their best.
Narrow beds ran the length of the garden, filled with white roses underplanted with blue lavender and thyme.
Layna was underplanting more white tulips with sunny-faced yellow pansies.
Mature honey locusts, their long branches reaching upward, were underplanted with sheared ilex and holly, still glossy green.