Planting Your Dahlia Tubers in the Ground

I love to over-give information, and sometimes people don't want to read that.  So I have started with simple basic guidelines.  But down below is my lengthy explanations.  

Where to Plant- Plant where you get a minimum of 6 hours plus of sunlight everyday.

Make your soil well draining.  I use bagged steer manure and organic peat moss worked into my soil to improve it.

Each Dahlia Tuber has different size plants, pay attention to the size as you pick your location.  And make a plan for how you will support the dahlias before you plant.  Single stake at planting, or add cage, or netting once they are about 12 inches.

You need at least 12 inches between your plants, and 18 inches gives it more breathing room.

Planting-  Only plant your tubers once the chance of frost has passed.  Dig a hole about 6 inches deep, mix a small amount of bone meal into the soil and lay the tuber sideways with the eye (think potato sprout) facing up, cover with dirt.  Place a name marker!  

Do not water the first couple weeks.  Wait until the dahlia starts sprouting above the ground to begin watering. 

Watch for Pests-  and deal accordingly.  Please try to use the stuff that is safe for pollinators!  Because the Dahlia flower attracts lots of pollinators and we want to protect them.  I use neem oil only during the growing stage and not when there are blooms and sluggo plus.

Once the plant is about a foot and has 4 sets of leaves, find the stem and "pinch" off the growth in the middle just above the 3rd set of leaves. (Or cut it).  This forces the plant to grow outward, not just single stem up, and you get a lot more flowers.  Easy and it pays off.

Once the plant is growing and several inches tall you can begin fertilizing.   Pick a fertilizer that is low-nitrogen (same kind as tomato plants)  and fertilize monthly.

Planting Instructions:   I like to remember that Dahlia tubers are similar in texture to a potato.  The tuber contains the nutrients and everything it needs to start producing a new plant.  The first couple of weeks a tuber doesn’t need light or extra water to produce an “eye” and start to grow.  Just good conditions so they don’t rot or dry out.

Beware of planting when there will be lots of rain.  Too much water in the beginning equals rot. Recommend to plant them in the ground only after the last frost has passed. Make sure the area you are planting gets at least 6-8 hours of sunlight.  Like anything you plant, to thrive you want to improve the soil.  I like steer manure and peat moss worked into the soil.  Be careful with topsoil addition or other additives because Dahlia’s are easily killed by weed preventers/weed killers. Important to stay away from those kinds of chemicals.

 Dig a 6-inch hole, lay the tuber with the eye facing up (ideally).  Cut any growth (eye) back to about 1 inch.  That helps strengthen the stems.  If you don’t have to worry about animals trying to dig it up, I recommend working in a little bone meal in the dirt after you dig the hole.   Cover with soil and then do not water until you see the green sprouts above ground (admittedly if I am feeling unsure, I will take a spray bottle and give it a couple squirts… but it is unnecessary unless you are planting in a container).  Once the sprouts are above ground, then water 3-4 times a week with a good long soak.  It is recommended to use a water system that puts water in the soil rather than spraying in the air (this is to prevent leaf damage and virus).  When the plants have 3-4 full sets of leaves it is beneficial to trim off the middle stem at the  3^rd set of leaves.  This creates more of a bush rather than a single stem.   Dahlias will need a support system, so placing a 3-foot stake in the ground when planting is good, tomato cages also work well as well as garden string and t-posts.   Every 3 weeks or so you can also fertilize with a fertilizer that you use with tomatoes.  Online they have lots of recommendations.  I have been experimenting with different kinds and I don’t currently have a favorite.    Most dahlias start to produce flowers after 80 to 120 days. Deadheading encourages more flowers.  ENJOY!

It is important to note that I am giving general guidelines.  If you live in a humid area, most of my personal experience and ideas will not apply to you the same way.  I happen to live in a very dry climate.