A crowded patch of irises is themost vulgar cause for a unsatisfying show of flowers . If you ’ve experienced a dissatisfactory kick of iris flush this spring , then it ’s probably time you divided your flag rhizomes .
While most gardener have done beginning part before , in the case of bearded and Siberian irises , we ’ll have to do a rhizome sectionalization . It may sound a fiddling bit intimidating at first , but it ’s really not hard to do ( and a very useful horticulture skill to have ) .
When should you divide your irises?
iris should be divided every 3 - 4 years .
The best clock time is about six to eight weeks after their expected bloom of youth sentence . You should apply this timeline even if your irises have skipped their flower period this twelvemonth . So for iris that would have blossom in May , you’re able to start thinking about divide them in other August .
One word of advice though : avoid split your irises too deep in the growing season .
This is because you want them to have enough sentence to get shew in their fresh blank well before the comer of cold weather condition .
Depending on how early on your winters put in , you might be able to wait until mid - September to divide your sword lily .
Here are the step to take for right iris rhizome segmentation .
Step 1: Collect your tools.
You ’ll need a well - sharpened gardening knife , a garden fork or a hand spade and a rag take in with rubbing alcohol to disinfect your blade when you move from one rootstock to the next . The disinfect wipe is not mandatory , but it ’s a near thought to have it handy if you surmise that your fleur-de-lis rhizomes may be suffering frombacterial soft rot .
One Son of advice : I mentioned that your shears or tongue should be sharp enough to dilute aright through the rhizomes without tearing them . This is really important because neat cuts are less likely to cause rootstalk rent that will make your plant susceptible to a bacterial flak .
Step 2: Trim back the foliage of your irises.
pop out by trimming back the foliage to about six to eight inches in peak above the crown . If you ’re not comfortable with cut back so much , then you’re able to cling to hack off about a third of the top . If there are any dead or damaged leaves , you’re able to cut them even shorter .
This step is optional , but it ’s very utile for a few reason :
Some gardeners prefer to switch off the leafage blade straight across , while others choose to shape the iris leaves into a fan - like structure , follow the natural increment pattern of the parting . It ’s up to you to prefer how to cut down the foliage , if you need to trim it at all .
Step 3: Dig out the iris rhizomes and inspect them.
If the iris root glob has already solidified into a compendious flock ( more likely to materialise in exhaust clay - heavy soil ) , you ’ll need a bit of leverage to lift it out of the earth .
mildly lift the rhizome out of the soil , but do n’t tug at them . This is where a trowel or a deal jigaboo will come in handy . Do n’t use a regular spade , as this may be too turgid for the job and damage the rhizome when you ’re digging .
Pull out the rhizome social system , then softly sweep off the stay filth or wash it off with a hose . This will allow you to have a adept feel at what you ’re left with . Here ’s what to get rid of to make indisputable you ’re only keep on the healthy rootstock :
toss away the rootstock that feel soft and kitschy .
This symptom is often accompanied by a foul smell . ( intrust me , you ’ll know it when you smell it ! )
It is most likely an indication of bacterial flaccid rot and you should be extremely careful not to spread it from one rhizome to another during division . This is where the disinfect wipe come in handy . Wipe the blade of your tongue between cuts if you notice foretoken of disease . There ’s no pauperization to dispose the entire rhizome ( especially if it ’s a large one ) , but cut off the part that have waste . Throw aside the rotted parts , but not in the compost .
Discard rhizomes that have holes in them .
This is a sign of the iris borer at study ( Macronoctua onusta ) , a cat that wad into the foliage and digs down all the fashion into the rhizome . Get rid of these rootstalk and of any caterpillar larva or ball that you may discover .
Step 4: Divide your iris rhizome.
First , protrude by absent the rootstock that are already grow separately . gear up them away . They ’re quick to go back into the undercoat .
Then for the remaining big rhizome structures , distinguish the sections that have naturally split off or deepen guidance . cut back the larger chunk off into separate sections , making trusted each is at least three to four column inch long , has healthy roots attached and , if potential , at least a couple of folio lover protruding out of the open of the rootstock . Leaves are of import for rhizomes because , through photosynthesis , the rhizomes get enough DOE to start putting out outgrowth again .
At this full point , you’re able to either choose to keep all rootstock you ’ve separate or you’re able to partake in them with others .
If you do n’t have enough elbow room to relocate the unexampled rhizome , you may make another nurseryman very happy by apportion your sword lily surfeit . In one of the neighborhoods I used to hold up in , there would often be iris rhizomes for sales agreement at back - to - school garage sale in the fall .
