Today: Jul 04 , 2020

Divide and Re-Bloom Bearded Irises

17 September 2015  

For best iris blooms, dividing is a must.  Easy steps to separation.  Best soil amendments for best gardens.  How to plant iris rhizomes and roots. 

Watters Weekly Garden Classes

September Classes

Sept 19 – Choosing & Using Appealing Shrubs – Shrubs are the backbone of a good design. They provide essential structure, beauty, fragrance and color with a great variety of shapes. Rock landscapes without shrubs tend to look strange, immature and lacking. Learn how to use shrubs to create simple but effective planting combinations for a design impact to WOW, all four seasons of the year. Free to gardeners that want more from their yard.

Sept 26 – Container Designs – Easy as 1-2-3. The fall plants have arrived, and this is the month to transition from summer blooming flowers to winter hardy pansy, viola, mums, kale, dusty miller and more. Expect inspirational color from your container gardens right through the holiday season to come. Students learn the best soils, foods and flowers that keep on blooming. Bring your empty containers and experts will be on hand after the class to help personalize your style. Free.

October Classes

Oct 3 – Choosing, Using & Planting Trees. Learn which trees to plant for privacy, shade, color, evergreen and blooms. We cover trees for every situation, especially small gardens, including trees for country gardens and trees for difficult sites. Plant trees for blossom, bark, fruit and colorful autumn foliage. With so many choices picking the perfect tree can be overwhelming, but not after this class. Our entire horticultural staff will be on-hand after this class to help with individual tree situations. Free tree planting guide to students after this class.

Oct 10 – RepellingAnimals – What’s Eating your Yard? – Deer, javalina, pack rats and gophers are just a few of the vermin covered in this class. Learn the 12 detestable plants animals absolutely will not eat and more. Repellents, fence, plants and techniques are all covered in this fast paced class. You can have an easy to care for yard among the animals, we’ll make sure of it.

Oct 17 – Bringing the Outside In – How to Bring Plants Indoors for Winter. There is a proper technique, unless you like spiders, worms crawling over the carpets and pesky fungus gnats. Students of this class can enjoy their geraniums (all winter), blooming jasmine, citrus and more. It’s easy and will save you money for next spring’s gardens.

Oct 24 – Herbs for the Winter Kitchen. Many plants like the winter season to come, including many culinary herbs. Learn which spices to harvest outdoors and which prefer to be planted in the kitchen window cell. Either way, you will be the kitchen hostess with the freshest herbs. Fun, fragrant and family friendly. This class includes free tastings from Watters non-GMO, all organic culinary herb collection.

Oct 31 – Irrigation and Winter Water. Local irrigation experts are on hand to answer detailed questions on all things irrigation. Do plants need water through winter? How can gardeners prevent freezing and more. This is a technical class, so come prepared with paper and pen. You will leave full of knowledge and lots of details.

November Classes

Nov 7 – Best Evergreens thru Winter – The autumn colors have dropped leaving the landscape naked and bare. As the last leaf drops Watters winter evergreen collection fills the garden center. Late fall is the ideal season for spotting evergreens trees in the naked spots of the yard. The best varieties, planting techniques, and evergreen care are all included in the class. ‘Living Evergreens Indoors as Holiday Decor’ is free for each student who attends.

Nov 14 – Keeping Critters Out – The animals can have a ferocious appetite in the yard, but not in your landscape. These simple steps will keep critters at bay. We will take special care to show plants the furry locals are known to dislike, some may even have a repelling presence to them. All the tricks in the book are shared at this class

Nov 21 – Top 7 Evergreens that Look like Christmas Trees – Go ahead and plant these winter hardy trees, they prefer the season. You can plant these local beauties keep them in their pot, or decorate and plant them after the holiday celebrations are over. Not all trees are created equal, but after this hands on class you will be able to spot the best trees from across the nursery.

Nov 28 – Decorating with Holiday Tropicals, Poinsettia & Christmas Cactus – The most garden fun is had with indoor tropicals and our holiday plant collection. The first of these festive plants arrive this week just for the event. Cooking the turkey dinner is fine, but these plant ideas bring out the kid in even the most avid gardener. Coupons abound for each of the students as we premier this year’s newest poinsettias, amaryllis and blooming cactus.

December Class

Dec 5 – Cut Christmas Trees and Greens & How to Force them to Stay Fresh – This is the week the freshest cut trees of the season arrive. We have a new featured tree that last longer than all the others this year. Students learn which trees stay fresh, care, and some insider secrets that insure your tree stays fresh until the very end. We have locally designed wreaths, swags, and garlands just for the students of this class. Free to all locals with a special coupon just for attending.


Bearded Irises are tall, elegant additions to a flower border but quickly can crowd and choke themselves in their garden space.   You can keep them blooming through regular division of the rhizomes, or roots, every 2-3 years. If left undivided, the flowers become small, decrease in blooming numbers, and become susceptible to pests and disease.  If your iris bed is over three years old, your garden will benefit from this column’s information.  

Divide bearded irises anytime after flowering, through the month of October. Using a pitchfork, carefully dig around the iris bed, starting about a foot away from the outermost edge.  Try not to pierce rhizomes with the fork. Gently lift the rhizomes out of the soil. Since bearded iris are grown at soil level, this is one of the easiest plants to lift.

Rinse off soil clinging to rhizomes - Once you have the iris rhizomes out of the ground, shake off any loose soil. Now rinse any remaining soil with a garden hose. If you don't have space to do this in the garden, it is sometimes easier and neater to do it over a tarp. Rinsing off the soil allows you to better see the rhizomes to inspect them for damage.

Once the rhizomes are cleaned, you can separate the individual rhizomes  from one another.  Don't break them apart just yet; only loosen the naturally delineated sections.

Cut back the leaves to 6” lengths.  Once the rhizomes or roots are clean, cut the foliage to 6 inch lengths. Cutting the fan of leaves connected to a lifted iris rhizome makes the plant easier to work with when dividing and replanting, and helps prevent water loss while the plant becomes re-established. The fan does not need to be cut symmetrically. Some leaves may be damaged and will need to be cut shorter than 6 inches. The leaves will start to grow back, with the middle leaf growing tallest.

  Inspect roots for borer damage and soft rot.  Once the roots are clean, inspect them for small to medium holes. These are signs of borer damage. If your iris leaves have dark streaks through them, you probably have iris borers. 

Also look for soft spongy spots. These indicate another common iris problem called soft rot.

Using a sharp knife or pruners remove any trace of either iris borer damage or soft rot and dispose of these segments.  Soft rot spreads easily, so disinfect your cutting tool with denatured alcohol between cuts to prevent spreading contamination.

Dividing Healthy Rhizomes - Now you are ready to divide the remaining healthy rhizomes. You will see natural places to make a split, such as where the rhizome has forked. Study to make sure each section you've chosen will wind up being at least 3 inches long and have healthy roots growing from it.  Now, Be Bold! Go ahead and make a clean cut through the rhizome, using the same sharp, disinfected knife or pruner.

Preparing the new iris bed - The final step is re-planting your divided irises. Choose a full sun location and start by re-amending your plot’s soil. 

Mulch, Soil Activator, 7-4-4 Food - Prepare the new bed by spreading a 2-3” inch layer of Watters "Mulch" then add "Soil Activator" and Watters 7-4-4 "All Purpose Plant Food" at the recommended rates. Mulch keeps soil loose so roots spread quickly. Soil Activator stimulates new Irises to form deeper roots. Watters All Purpose Plant Food feeds the plants for maximum flower size with brighter colors. Blend these amendments into the soil to one shovel’s depth and then rake the surface smooth.

The garden is now ready for planting.  Only 2-4 inches of soil should cover each root. If planted too deep, flowers will be small or completely absent.   Keep the iris bed looking natural by replanting roots in triangular formations.  

Water thoroughly using Watters "Root & Grow". This liquid root stimulator encourages strong new root hairs to form, and starts the growing process of next spring’s plants. Use “Root & Grow” every 2 weeks for the first 3 months to maximize roots and blooms.

When finished, you’ve done the work necessary to guarantee another couple of years of beautiful, carefree, iris blooms. 

Plant of the Week

Instant Raywood Ash

  •  Raywoods are known for their handsome fall foliage that turn colors of red to royal purple, just stunning.
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Ken Lain, the Mountain Gardener

Ken Lain is attracted to sunshine, beauty, happiness, success and health through gardening, and wishes to point the way to others. Throughout the week Ken can be found at Watters Garden Center located at 1815 W. Iron Springs Rd, Prescott, or contacted through his web site at