of my 2-year-old citrus trees show spiky growth that is dark green
and comes from the base of the stem. Some plants still have their
original stem growing, but with others it has died off. The site
is quite windy with occasional moderate frost. Should I do anything
or just let them grow out?
spiky shoots are suckers growing from the rootstock. Most citrus
varieties in this country are grafted on to a root-stock, Poncirus
trifoliata, often called simply trifoliata. It tolerates our
cold, wet winter conditions so we can grow a wide range of citrus
fruits which would otherwise need more tropical conditions to crop
Trifoliata has long thorns
and each leaf has three distinctive leaflets - hence the name trifoliata.
It sounds as if your young trees have suffered from stress of some
kind, perhaps lack of water or lemon tree borer, which has stimulated
the rootstock to send up shoots from below the graft.
Those trees where the
original branches have died need to be replaced - they won't recover.
With the others you need to remove the suckers as soon as possible
to force all growth into the desirable fruiting parts of the tree.
Cut the suckers, or pull them off as close to the main stem as possible.
If they're small enough,
break them off with a downward pull, but take care not to tear away
a large strip of bark. If they're growing from below ground, scrape
away the soil so you can remove as much of the sucker as possible.
Be alert for more suckers from the same area in the future and remove
them while small.
To reduce the chances
of it happening again buy the healthiest looking plants you can,
keep them well watered during dry periods for at least the first
couple of years and fertilise in spring and autumn. Remove all fruit
as it forms for the first couple of seasons to reduce stress on
the young tree and to encourage strong branch growth.
It's worth noting 'Meyer'
lemons are often grown from cuttings as they do quite well on their
own roots in most areas. So if your garden centre can sell you a
cutting-grown 'Meyer', you'll have no problem with suckers.
Gardener, Issue 169, 2005, Page 28
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.