By Vanessa Spady
When it comes to growing iris, soil conditions will often dictate the quality and quantity of your rhizomes and blooms. Sure, other things make a difference as well—I for one think that a zesty combination of spoiling and neglect make for happy plants, but that’s for another post. About the soil...
Our little Comedy of Iris garden is located in central California, in a primarily agricultural area, which means we have a nice amount of space to start with (about an acre of open, slightly sloped land), but also some significant challenges when it comes to the dreadful native soil. As I mentioned previously, our soil has two basic textures—pudding when it rains, and concrete the rest of the time.
Luckily, the nutrient level is very low! (Hooray?) So trucking in good soil and amendments was a necessity. I had six yards of a really lovely loam delivered, and much to my astonishment, I have used it all. But, only the best for my newly purchased rhizomes, because, let’s face it, I want to see massive glorious blooms in the Spring!
Additionally, our hard ground is home to several kinds of critters that love it when we water—it makes the soil soft for them to dig through, and gives them something tasty and nutritious to eat. I, personally, do not like killing critters when they are in their territory, but no amount of reasonable conversation makes ground squirrels understand that they should go around the foundations of your barn when tunneling across your property. And gophers don’t care that the plant they just destroyed was a gift from your recently deceased mother... it was moist and tasty! Basically, any time you add water to our land, you attract the very vermin you want nowhere near your precious plants. Ugh.
Furthermore, it gets very hot here, and it’s quite dry. Because this is basically an irrigated desert, it’s over 100 degrees for weeks at time—so, really hot. And managing the watering (which requires more care during a drought) is also critical. Iris don’t like to be too wet (or they rot), and managing their moisture and nutrients is crucial for them to propagate and increase. But creating moisture means attracting critters that will eat their roots, if not the entire rhizome... wheeee?
So, even after we had good soil brought in, we faced challenges in keeping critters out of the beds, and not losing our stock to heat or rot. Time for some creative solutions.
When I was gardening back in my suburban setting, the soil was decent, critters were few, and the water was a spigot away... it was easy. All I had to do was not over-water, and feed once or twice a year, and I had gorgeous, happy iris all the time. After moving here, with the more challenging conditions, I have tried a variety of solutions, after losing most of a bed of named iris to a ground squirrel.
When I first planted iris in our country soil, they did so-so. I didn’t initially know how to manage the soil moisture and feeding was completely different here. But once I got it figured out, I saw lots of green growth, and happily awaited my first blooms. But they never came, and the number of rhizomes seemed to dwindle. Finally, a bit of loose soil at the back of the bed exposed the dirty truth: a ground squirrel had tunneled into the bed, from under my barn. He had been snacking on my lovely iris from beneath, and I hadn’t noticed him for weeks. This is when it started to get a little Caddy Shack...
I took up the few remaining iris, and dug out the entire bed to a depth of about one foot. I molded tight-weave chicken wire into an open-shoe box shape, and laid it into the hole where the bed had been. I then re-filled the bed, and planted a new batch of rhizomes, confident I had outsmarted the little blighter. Joke was on me, though. Several weeks later, as I was watering, I noticed a bump of loose dirt near the outside edge of the bed, and that dirt was moving.
“Ha!” I thought triumphantly to myself. “He’s just run into my chicken wire basket, and can’t tunnel his way through it!” I quietly laid down the hose, and watched to see what would happen. The little guy pushed the dirt out of the tunnel and popped his head above ground. I could see him looking around, so I held perfectly still. He ducked in again for a moment, then came up again, and to my outrage and astonishment, he got out of his tunnel, walked over the lip of the chicken wire barrier, and began to tunnel down into the bed, right in front of me!
The hours spent digging out the bed, making the chicken wire barrier, placing it in so carefully, and replanting the whole bed was undone in one moment. I had been played by a ground squirrel!
All bets were off after that. I dug up the remaining rhizomes from that bed and moved them into pots, but I never liked that solution, nor did my plants. Then I struck on using pallets as beds, which did a good job once I got the soil combination right. I placed the pallets on rocky ground, where the squirrels don’t really dig, and then filled all the slats with a combination of native soil, amendments, and planting mix. This had the added advantage of making it simple to keep iris from one bed or section from creeping into another section. I kept only one kind of iris in each pallet, and there was never any confusion. If we ever have an emergency, I can pick up the entire pallet and move it, bed and all.
We knew from the beginning of this project that just digging up a little bed in the ground and plunking down the rhizomes was not going to be the method for success. For this initial growing year, we are trying a combination of kiddie pools mounted to pallets, raised beds (with a base of weed blocking cloth and wire mesh), and tires (with the same wire and cloth base). We cleared the surface of the soil of the dried and dead native growth (code for “weeds”), and began to layout the different kinds of beds we had to see how they might best work with the kinds of iris we ordered.
This was our preliminary layout, after we cleared the weeds, but before we put down the weed blocking cloth and wire. Ok, and before we painted the tires.
We opted to use only one level of these raised beds for this first year to see how they would do.
To give the iris the best chances for success, separating them from the ground was the smart move. Besides, I don’t want to encourage any further comparisons between myself and Carl from Caddy Shack.
The project has expanded considerably since this first phase, so you’ll have to keep your eyes peeled for updates and new photos. And you can bet there will be another load of the gorgeous loam heading our way sometime in the near future. Please, just don’t tell the gophers or ground squirrels.
And because I promised I would, here is a wonderful iris from Chris’ garden:
'Leave The Light On' ( Riley Probst, R. 2013) Seedling #U4WHXHM. IB, 22 (56 cm), Early, midseason and late bloom. Standards blue-purple with 1/16th gold edge; style arms bright yellow, vertical purple veining on style crests; falls blue-purple luminata pattern, bright yellow area with 1/4" white spear extending downward from beard; beards orange; pronounced sweet fragrance. 'Wild Hair' X 'High Master'. Fleur de Lis Garden 2013. Honorable Mention 2015.