Building the Propagation Environment LAT 109

What does the propagation environment have to do? Depends… on what you’re propagating and where you are. Hardwood cuttings Softwood and semi-hardwood cuttings Seed propagation

For semi-hardwood and seed prop Provide a low-water loss environment – High humidity Provide protection from the elements – Cover Provide light (but not too much) – Open, but shade if necessary Provide a temperature conducive to rooting (germination) – 70 to 75° F

Key features Structure Cover Raised bench Drainage Intermittent mist Bottom heat Light/shade system

Structure Glass house Hoop house Cold frame Outdoor beds Other?

Cover Clear 6 mil poly is commonly used Polycarbonate Glass

Raised benches Provide better drainage and an ergonomic workspace. Sanitation is easier.

Drainage Ground cloth Gravel Permeable pavers Concrete (with drain tile) Proper grade Critical if propagating on the ground!

Intermittent mist Water source Piping Nozzles Mist timer Day timer Turn on in the morning, turn off at night Every 8 minutes for 8 seconds is typical

Bottom heat Electric – Cables – Mats – Thermostat Water Goal is ~70°F

Light/shade system Shade cloth – Summer – Reduce UV – Reduce temperature – Sold by % shade – Automated systems Supplemental light – Induce flush of growth – Tricks the plant into thinking long days (short nights)

Light interruption to induce growth Winter = short days and long nights = minimal growth Summer = long days and short nights = growth Light interruption = short nights = growth

Avoiding diseases Major pathogens – Soil born pathogens – Root rots – “damping off” or “foot rot” – Water molds Pythium (wet & cool) and Phytophthora (wet & cool) – True fungi Rhizoctonia (wet & warm) and Fusarium (variable)

Strategies Cultural – Disease free plants – Clean tools – Clean facilities – Clean containers 10% bleach – Sterile media – Work in a separate area from mist bench – Environmental conditions – Monitor daily Chemical – Fungicide Soak cuttings prior to sticking Drench beds after sticking – ases/rpds/615.pdf ases/rpds/615.pdf

Conifer cutting propagation

Easy-ish to propagate conifers Cupressus Chamaecyparis Thuja Juniperus Thujopsis x Cupressocyparis leylandii Taxus Cryptomeria Tsuga Calocedrus

Types of conifer cuttings

Our protocol today 4 to 8 inches long terminal (tip) cuttings with some wood are most often used. However, you can try heel and mallet cuttings as well. Remove foliage from lower half Trim foliage (tops) if necessary Basal wounding can help Using Wood’s rooting hormone (1.03% IBA), we’ll want to mix up 10 oz of 3000 ppm IBA to be divided among the benches for our 5 second quick dip. How much Wood’s do we add to how much water to get 10 oz of a 3000 ppm IBA solution? Insert ~ 2 inches into propagation media e.g. Cupressus, Chamaecyparis, Thuja, Juniperus, Thujopsis, × Cupressocyparis leylandii, Taxus, Cryptomeria, Tsuga, Calocedrus Today we’ll use the 6-cell packs for our conifer cuttings. Each student is to stick a minimum of 12 cuttings (2 packs per person) Remember: 10% bleach to sterilize pots, 1:2 peat:perlite media, LABELS, all cuttings go on the mist bench in the West greenhouse.