The Lime Tree and the Lemon Tree

A tale of two citrus…

Sam: Planted both about four years ago. The Tahitian lime roared up and the Meyer lemon just remained a dwarf. Despite a healthy crop of fruit this year.
Helena: Tahitians are vigorous. And Meyers are semi dwarf and often grafted onto dwarf rootstock. That could explain it.
Sam: There’s also kikuyu. 
Helena: Oh yes. Kikuyu is a notorious invader around here. I see it in your lawn.
Sam: I wondered about that. Competing for resources like water, oxygen, nirogen in the topsoil?
Helena: Oh yes. Less so for a vigorous chap like the Tahitian, his roots go deep. But the kikuyu also can release allelopathic compounds inhibiting growth of the shallower rooting Meyer.
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Voice-over
So there’s some reasons for the height differences between the lime and the lemon. Genetics, rootstock, and an invasive species. Celebrity gardener Helena may have some thoughts on controlling invasions later.