Welcome back to SwensonGardens.com blog! Had to take a few weeks off from posting before the main events start happening with peony digging, dividing, shipping, plant backs and mulching. Where in the world has this summer gone? Yikes seems like yesterday we were anxiously awaiting our first peony blooms. All is looking great in the fields with rains coming at just the right time. Had another 1/2 inch of rain over the past few days.
Gardeners often ask us ‘should we water our peonies’? Well yes and no. I’ll try to keep this on task and verbally easy to follow. For our gardening friends in USDA Zones 6-8a the answer is a resounding yes IF you are located in dry and hot areas. Our friends in coastal Oregon and Washington who are Zones 7 & 8a that receive more rainfall and lower temps the answer is a resounding no. For the dry and hot 6 to 8a’s, the key to watering is slow and making sure the site dries out under ground level between watering. If your site remains constantly wet above and roughly 5″ below ground level, the crown and storage roots risk the chance of rotting out from too much watering. We suggest using 1x slow (maybe 1 to 1 1/2 gallons per root) per week. If you stick your index or middle finger into the ground around your site location and it comes up with muddy dirt, -DO NOT keep watering it until your finger comes up without any mud on them. IF your fingers come up dry and no rain is forecasted, you may want to water as described previously. WHERE TO SLOWLY ADD WATER? DO NOT WATER INSIDE OF THE PEONY STEMS!!! Peonies are similar to shrubs, conifers and deciduous trees where they receive moisture at their drip line. So on peonies water around the drip line of your plants. This affords the greatest relief from keeping your crown inside the stems dry. Now, STOP WATERING AFTER LABOR DAY SO YOUR PEONIES CAN PREPARE FOR DORMANCY! Give them one last drink of water just before the ground freezes or roughly speaking around mid-November when temps start to reach the mid-30 to lower-40 degrees at night. This will tide them through until next years growth cycle.
Now for our gardening friends in Zones 2-5. Watering gets a little trickier and should only be done in drought years (which for us is thankfully not occurring). Not to be too negative, but every year we receive calls from gardeners who inform us that their peonies did not come up or came up and died. The first question we ask them is ‘have you been watering your peonies?’ Answer is yes in the majority of cases. Now in the case of wet springs like the springs of 2013 and 2014, we have no control over how much our Creator decides to give us. So here’s the deal; watering, drip lines and irrigation spray heads are a ‘no go’ with peonies in these zones. Watering peonies will not help them grow any faster than letting them do their own thing. Footnote though for gardeners on ‘sand’ and ‘sandy loam’ soil, you may need to follow as described in preceding paragraph for Zones 6-8a. Peonies are very drought resistant. What happens in a drought year is they may seek dormancy earlier and their next years growth may not be as great as a normal moisture/temperature year. It is wiser to error on the side of dry vs watering too much.
The normal rule of thumb for peonies is roughly the same as grass in your yards – one inch per week of water. In all zones as mentioned above stop any and all watering after Labor Day to start their dormancy cycle. Then before the ground freezes in zones 2-5 give them their last drink for the winter. If planting new peonies as described by our planting tips, it is best to water in at time of planting and then again one time right before freeze up and/or temps start to average mid-30’s to low-40’s at night.
If you have any additional questions regarding watering peonies, do give us a call or email!
Happy peony gardening!