What are key events I shouldn’t miss when growing this crop?

Planting: Planting begins mid-May to avoid frost damage and cold substrate, delaying essential growth. Frost protection may still be required in some locations. Place the pots already spaced on the bed. Each time the ‘Ellwoodii’ is moved (damaging roots), it causes stress and imbalance in nutrient uptake, making the plant susceptible to disease.

Growth Rate: Measure the plants’ height at regular intervals to ensure even growth. The ideal height increase is 1–1.5 cm (0.4–0.6”) weekly. With the right conditions, growth will continue into October.

Trimming: Trimming the plants up to three times during the growing season may be necessary to minimize natural variations in size often seen early in the growth cycle. The timing of the trims may vary, but weeks 27–31 fit best with the growth stage in the Pacific Northwest. Each trim must remove no more than 1 cm of top growth, setting a trimmer height to reach only the tallest plants. Any subsequent trims will catch more plants as the crop evens out in height.

What soil do I need?

Use up to 100% coarse peat, utilizing other substrate components where needed to improve porosity. The pH must lie between 4.5–5.0 throughout the entire growing cycle. A higher pH is likely to lead to brown-tipped foliage. Adding bark or wood products to the substrate may reduce the nutrient buffering capacity, potentially leading to brown-tipped foliage. Amendments such as clay or organic matter can also increase nutrient buffering capacity.

What kind of environment do I need?

Ideally, this crop is grown outside in full sun, but it can be managed in a greenhouse. Airflow around each plant is vital. Irrigation cycles should be run in the morning but must be finished by 3 p.m., allowing foliage to dry before nightfall.

Heat stress (>34ºC/93ºF) can be managed with irrigation cycles in the early afternoon.

Frost protection may be necessary in the early part of the growing cycle, which can be ideally achieved through pulsed overhead irrigation. Moving the crop inside a greenhouse is the easiest form of protection in the later part of the year.

What kind of fertilizer strategy should I have?

After transplanting, irrigate with clear water until the input begins to root into the new substrate, then start fertigation.

‘Ellwoodii’ uses N very efficiently, so use a lower N fertilizer balanced with potassium and calcium. This fertilizer should be primarily nitrate-N-based.

Monitoring EC in the substrate will guide your fertigation decisions.

Using a 2:1 method, the targets are as follows:

• 1.0EC up to Week 36 
• 1.8EC Week 36 onwards

Using controlled-release fertilizer (CRF) is not recommended.

What kind of pests should I anticipate?

• Aphids (vector of disease)
• Pestalotia (often a sign of excessive and weak growth due to higher nitrogen fertilization)
• Pythium
• Phytophthora
• Phomopsis
• Fusarium