How To Grow Dahlias

Basic Needs

For late blooming varieties, earlier blooms on others and delayed spring weather.

Prefer rich, sandy, well drained soil. Will tolerate other soils that are not too wet.
Use raised beds in wet or poorly drained areas
Remove all weeds and roots
Add manure, compost, decomposed leaves, etc.
If using fertilizer, use low nitrogen for vegetables or flowers
Soil ph, prefer between 6.5 and 7

Plant when the lilacs bloom and the corn is planted
2 feet apart unless a dwarf variety, 2.5 feet for very tall varieties, 1.5 for dwarfs
In holes 1 spade depth deep
Put a stake, of suitable height for the grown plant, in the hole
1 tsp 6-8-6 in the bottom of the hole, cover with soil
Tuber on its side. Eye/shoot close to the stake about 6 inches below the surface
If it has a shoot, leave the top exposed and fill the hole in as it grows
Very little water after planting, until growing well. Tubers rot easily.
Protect against cut worms and slugs by placing a toilet paper roll, partially buried in the ground, around the shoot

1 inch of water a week from rain or by deep root soaking with irrigation or soaker hose.
Tie to stake every 12 inches or so
Prefer cool roots, mulch late in June after earwigs have nested
If using fertilizer, 1 heaping tsp of super triple phosphate 0-46-0 per plant every three weeks from when the plants are 12 inches tall until late August. Water in well. This gives strong roots and stems and lots of flower
Late July add 1 Tablespoon of Muriate of Potash 0-0-50 every 3 weeks until the end of September. Potash builds big, strong tubers.

Stops the upward growth of the main stem of the plant
Creates a shorter, bushier plant
Allows for more flower development
Done when the plant has 4 sets/pairs of leaves
Part leaves and snap off the centre growing stalk just above the 4th pair of leaves. You could use a knife or scissors if you wish

Creates longer stems on flowers, better for cut flowers
More energy per bloom so bigger blooms especially in the large and giant varieties
Dahlias grow buds in groups of two or three
When the buds are small but can be individually seen, pinch out the smaller side bud(s)
For long stems you may need to take off one or two sets of leaf side shoots. Depends on the variety.

Strong, healthy plants can thrive in spite of some insect damage
Soap and water sprays control most problem insects
Clean cut broken stems to reduce the chance of bacterial infections
Cut off rotten stems well below the infection so it doesn=t spread to the tubers

After killing frost or 1st of October
Tubers rot in cold, damp soil, even if not frosted on top
Cut off top, 6 inches above ground
Leave for a few days up to 1 week to allow eyes to set
Tie label on stem
Dig with a long-bladed spade 9 - 12 inches from the stem. Must be a complete circle with overlapping cuts to sever long roots
Using the spade, lift the tuber clump
Clean the worst of the earth off
Wash clump and leave on its side to drain and dry for 24 hours, protect from frost.
Split clump removing broken, rotten, diseased, old and eyeless tubers
Leave to dry and scab over cuts for 24 hours
Place in storage medium (vermiculite, shavings, peat, etc) and containers.
Store cool (about 5C, 35 - 45F) and dark