It might seem early, but this summer is actually the perfect time to begin preparing next year’s cut flower garden.
You may still be in the dreaming phase of growing dahlias, or you may be planning to expand your dahlia patch. You may even be considering growing in a different spot next year, if you’re not happy with your dahlias’ experience this summer. If you find yourself in one of these situations, I’m writing this article specifically for you, and I hope you’ll find these four essential preparation suggestions helpful.
Carefully Site Your Garden
Dahlias require full sun to grow well. The technical definition of full sun is at least 6-8 hours of direct sunshine per day, but we’ve found dahlias thrive with even more hours of sunlight here in the PNW. We grow ours in fields where they receive sun from sun-up to sunset, but most home gardens will have to deal with some amount of shade from trees, structures, or landscaping. If you’re in a hot climate, situating your dahlias with afternoon shade will give your dahlias some relief from the heat, and can work to your benefit. However, if your garden area has too much shade, your dahlias won’t thrive.
You can observe your potential growing space right now, to make sure it’s getting enough sun in the crucial days when the dahlias should be bulking up, or continuing to build root systems and foliage so that they can bloom like crazy from mid-summer through fall as days shorten. To prepare for next year, journal how many hours of morning and afternoon sun you have each week of the growing season so that you’re sure you’ve sited your dahlia patch well. I’ve seen several options of sun meters that you could use if you don’t have time to observe each week, but we haven’t trialed any of these products. We highly recommend observing with your senses if possible, as you’ll certainly end up learning a lot more about the garden site you’re prepping than just the full sun hours.
Soil Preparation
Dahlias love growing in porous, sandy soil. Growing them in very heavy soil, like clay, will allow too much water to sit around the tubers and roots, potentially causing them to rot during the growing season and compromising their storage viability. If the soil in your planned new garden space is too heavy, you can amend it right now, and again in the fall to promote airflow in the soil. You can add compost, leaves, and/or other organic material to your garden space now. Either layer your organic additions thickly over existing grass/vegetation to smother it, which will begin making an area that will attract earthworms and other subterranean decomposers (beneficials!), or begin tilling organic additions into the soil where you want to grow dahlias next summer. You can also add in sand to the growing area along with the organic material to increase porosity and drainage. In order to be sure your dahlias stay healthy while growing and also while in storage, be sure you plant them in an area that drains well, and is not too low or prone to collecting puddles.
Make an Irrigation Plan
Dahlias need enough water each week after sprouting to keep the soil around them moist. You don’t want your dahlias to dry out and wilt, or it will stall their growth for a week or more. You also don’t ever want them sitting in water, which is why siting and soil preparation is very important. This summer, assess the rainfall that is typical for your area by looking up historical rainfall and also using a rain gauge and journaling what actually happens in your garden. If you see that you get about 1” of water in your garden each week then you may not need supplemental irrigation. (One inch of irrigation per week is a fairly good rule of thumb for dahlias, but we recommend feeling the soil to assess each week rather than solely relying on that measurement.) If, like us in the PNW, you experience drought-like conditions in the growing season, then you absolutely need to plan for irrigation. Here is a summary of our advice on watering dahlias. Use the time you have this summer to make a good plan to see the best success in your dahlia garden next summer!
Get Ready to Order Dahlia Tubers
It might feel too early, but experienced gardeners know that the time to source flowers for the following season is the time when you’re harvesting them this year. For dahlias, this means that you need to start lining up next spring’s tubers in late summer and early fall. You’ll likely find suppliers offering tubers in late winter and early spring for gardeners who want to add them in last-minute, but if you want to plan well and have the best selection, pre-purchase any new tubers for next year before spring arrives. Our Triple Wren Dahlia Tuber Pre-Sale happens in late August or early September each year, and our Rooted Cuttings Pre-Sale happens later in September. Since you’re subscribed to our email list, you’ll get the first notification when our public sales begin, so make sure our emails don’t get lost in your inbox, and keep an eye out for the upcoming sales alerts.
