Citrus Roostock Sucker? Look at the Thorns

Q. I'm not sure if the branch at the bottom of my lemon is a sucker or a real branch.  I know if it comes from below the graft to remove it, but I can’t see where it comes from exactly. The leaves from this growth are huge, too.  It's about 6-8 inches from the soil.

Picture of trifoliate orange thorns

A. Look for long thorns. The rootstock used for citrus in our climate is frequently trifoliate orange, which produces an extremely sour, nonedible citrus fruit. It has huge thorns, up to 2 inches long! If this growth does not have thorns, or it they are small, it is probably lemon. The sucker is right on the edge, but I think it is coming from the scion (lemon).

            If you applied compost to the tree as it is growing, it may make some huge leaves. If you use compost as a fertilizer, apply it each year after you harvest the fruit. Water it in thoroughly.

            If you applied woodchips to the soil beneath the tree, apply it in a larger area under the tree as the tree gets bigger. Apply enough so it is at least four inches deep. Keep woodchips 6 inches from the trunk or it can rot it.