Peter Cun­dall:

Suck­ers can be a night­mare for vul­ner­a­ble plants and if not con­trolled will com­pletely take over, so the best thing to do is act im­me­di­ately even if this means tak­ing out the full root, ad­vises PETER CUN­DALL

Sunday Tasmanian - Tassie Living - - CONTENTS -

Act now to en­sure every­thing will come up roses

Many grafted trees and shrubs are prone to send­ing up lots of use­less but pow­er­ful suck­ers. They are dif­fer­ent from nor­mal, vig­or­ously healthy shoots be­cause all sprout from be­low graft­ing unions, emerg­ing from root stock on to which many trees and roses are grafted.

Suck­ers com­monly ap­pear around fruit trees, es­pe­cially plum, ap­ple and some cit­rus va­ri­eties.

Other trees may ap­pear to pro­duce suck­ers, even form­ing thick­ets of vig­or­ous stems, par­tic­u­larly hazel­nut, fig and mul­berry va­ri­eties. How­ever, these trees are ei­ther prop­a­gated from cut­tings or in the case of hazels, from di­vi­sions, so these wor­ry­ing ‘suck­ers’ are nor­mal healthy growth.

Suck­ers can be a night­mare with vul­ner­a­ble plants and if not con­trolled will com­pletely take over, dom­i­nat­ing and stunt­ing growth grafted on to them. Al­though root stocks are re­lated to scions, they al­ways look slightly odd and al­ways pro­duce alien blooms, in­fe­rior fruit or dif­fer­ently shaped, pale-coloured leaves.

There are sev­eral rea­sons why grafted plants sucker. The most com­mon is

Right now suck­ers are in full, ac­tive growth and are just be­gin­ning to store car­bo­hy­drates to give them a fly­ing start

dam­age to lower bark or roots be­fore or after plant­ing. Rose bushes are a typ­i­cal ex­am­ples. Of­ten when plant­ing new, bare-rooted plants in win­ter, bright green sucker buds can of­ten be spot­ted on or near dam­aged roots. These should be im­me­di­ately cut out, even if means tak­ing out the full root.

All rose bushes and climbers have a ten­dency to be­come top-heavy. That’s why even the small­est, stick-like new plants must be firmly staked and se­cured right from the start. When wind causes un­sup­ported plants to rock to and fro, roots are torn, mak­ing sucker growth in­evitable.

The worst ex­am­ples of roses suck­er­ing can usu­ally be found in gar­dens where the soil around the plants are reg­u­larly cul­ti­vated. This type of thought­less dig­ging dis­rupts root sys­tems, weak­en­ing plants and stim­u­lat­ing forests of pale­green, thorny suck­ers.

One way to re­move and con­trol rose suck­ers is to grasp stems firmly with gloved hands and forcibly drag them from

the ground, al­ways pulling away from plants. How­ever, with young roses, there’s al­ways a dan­ger of pulling en­tire plants rose from the ground, roots and all.

I pre­fer to in­sert a sharp spade just the in­side each sucker then slice down­ward, cut­ting cleanly through of­fend­ing roots be­fore drag­ging them out.

This con­trol is best car­ried out in sum­mer when plants are in ac­tive growth. While it can­not put an end to se­ri­ous sucker prob­lems it is more ef­fec­tive than do­ing the job in win­ter.

Rose plants grown from cut­tings can­not sucker be­cause they are not grafted. How­ever, while rel­a­tively slow to be­come es­tab­lished, they have a far longer life than grafted plants. Some of the old­est climb­ing and bush roses in Aus­tralia have been grow­ing for over a cen­tury and all are on their own roots.

The most con­spic­u­ous suck­ers emerge from the stan­dards of weep­ing trees. These trees cost a lot be­cause many have two or more scions in­serted, some­times up to two me­tres above the ground. The long-stemmed root stock can take sev­eral years of train­ing to fully de­velop.

When tufts of weird-look­ing growth emerge half­way up the stems of weep­ing stan­dard trees or worse still, pow­er­ful shoots that, in­stead of droop­ing, reach for the sky, they are suck­ers. Cut them off flush with trunks and don’t leave stubs.

Right now suck­ers are in full, ac­tive growth and are just be­gin­ning to store car­bo­hy­drates to give them a fly­ing start in spring, even after a sav­age win­ter prun­ing. Cut­ting them out now mas­sively re­duces the amount of stored en­ergy they can ac­cu­mu­late, dras­ti­cally weak­en­ing spring growth.

Many es­tab­lished lilac trees still grow­ing in old gar­dens were orig­i­nally grafted on to closely-re­lated privet stock which is no­to­ri­ous for suck­er­ing. In the past I was of­ten asked to in­ves­ti­gate why old lilacs had stopped flow­er­ing, usu­ally to dis­cover enor­mous privet suck­ers to­tally sur­round­ing a tiny, half-dead and com­pletely sup­pressed lilac.

These days most lilacs are grafted on to ei­ther seedling lilacs or Ja­panese tree lilacs. Even so, when newly-pur­chased are planted – prefer­ably bare-rooted in win­ter – the plant­ing holes a dug ex­tra-deep. This en­sures that the graft union is also buried al­low­ing scion-wood to de­velop its own roots above the graft.

Even­tu­ally the ‘nurse; roots down be­low wither away and the plants fin­ish up on their own roots, elim­i­nat­ing any dan­ger of suck­ers ap­pear­ing.

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.