From Tuber to Bloom: Part 1

Today continues our brand new grower series:

So your dahlia tuber or cutting has arrived!! Now what? There are a few things you want to check. I’ve written up a really good blog on this before so I’m going to point you there instead of re-writing (b/c that really wouldn’t make sense). Hop over there real quick and take a read.

Planting:
Now if you did you homework last week, you will have made your decision on where to plant. Planting is very easy- people try to make it complicated but let’s simplify. For tubers, dig a hole. If you have well draining soil, then you can dig 6” or so deep. If you have heavy clay, go 3-4” deep. If you have done your soil test and amended according to the directions in it, you don’t need to add anything extra to your hole. Place the tuber in the hole with the crown facing up. If you don’t know where the crown is (it’s where the sprouts come out), lay the tuber horizontally. The good thing is that even if you put it upside down, it’s still going to work. That sprout will find it’s way up!
A rooted cutting is planted very similar. Dig a hole about 2” deeper than the depth of your pot. Strip off the bottom pair of leaves from your cutting and make sure the node (where the leaves join the stem) is underground. This will help your cutting grow more tubers. Water it in well.
For more planting info: Go here and here.

Support:
Dahlias need support- most varieties grow a minimum of 3’ tall and around 4’ on average, occasionally 6’. So you definitely want to give it a little help. There are several ways to do this. On a small scale for a few plants, place a stake (3-4’ tall) next to your tuber/cutting when you plant it. (Don’t stake tuber planted dahlias later b/c you’ll pierce your tuber clump). Tomato cages also work well for single plants. Horizontal netting with 6” squares works well for full beds of dahlias. Sometimes 2 layers can be required. Twine woven through the plants and wrapped around stakes can work as well. Put your support in before you think you need it (b/c they’ll grow faster than you think!)

Weeds:
They are inevitable in any kind of gardening. The best strategy is to not let them get out of control but this is easier said than done. Don’t worry, we’ve all had the day that made us want to quit growing things because of the weeds. Using some stray or chip mulch from the beginning will help. Tuber grown plants will push through either type of mulch so you really can put it down from day 1. Some people use landscape fabric with holes burned into it. We found this to be too hot for our climate but in cooler climates it may work successfully.
For more weed control tips: The Mulching Chronicles

Watering:
We talked of securing access to water in the first blog so now it’s time to use it! Hand watering works just fine if you have the time and can be quite therapeutic at the end of a long day or to start your day. Automated drip irrigation systems are great too! They ensure your dahlias get watered evenly and on a schedule. Do whatever fits your daily life. But most importantly, don’t forget to water. If planting tubers, don’t water until they sprout unless your soil is very dry and it’s really hot! But generally speaking you want the tuber to sprout before you start watering but green on top, means roots on the bottom to use that water. Once you see buds on your plants, you’ll want to increase your watering. They will flower more profusely with more water. Most really hot climates will need water each day.

Fertilizing:
Your soil test should give you the first clues as to how to fertilize. You’ll need to amend according to what the test says. Do this before planting. We then add a fertilizer higher in nitrogen than potassium and phosphorus when planting as this aids green growth. After about 2 months, we switch to a fertilizer with higher potassium and phosphorus as this aids flowering. You can apply these as granular or liquid sprayed on the leaves or watered in. Either works!
Don’t get too hung up on brands either. Look for the nutrients you need. Different brands are popular in different places but they usually have the same nutrient combos. We apply fertilizer every 2 weeks during the flowering season. During green growth, we apply at planting and about a month later.

“Homework” for the week:
1. Decide on your support method and acquire supplies
2 Develop a schedule/plan for watering your plants
3. Source your fertilizer and a method to apply it.

This post has just skimmed the surface of how to be a successful dahlia grower. If you’d like to hear me teach live about getting your dahlia garden started right- I’m hosting a “Dahlia Bootcamp” on March 12 inside The Petal Society. It will be a live workshop - we’ll have dahlia giveaways, plenty of Q&A time, and everything you need to know to get started successfully with your dahlia garden this Spring!