As the poinsettia growing season arrives at nurseries throughout the UK, technical sales manager Joe Barfoot discusses plant health and nutrition for poinsettias:
Encouraging strong rooting in poinsettias
Poinsettias are a major seasonal crop for many growers, and as with any successful crop building strong foundations are vital. Poinsettias need to be supplied with the correct amount of nutrition throughout their growing cycle to produce a bold colour and healthy canopy. A strong root structure will help the plant uptake the nutrition supplied effectively, maximising input efficiency.
Rooting can be encouraged with combined applications of Kelpak and O-Phyte. Both work synergistically to encourage root branching and increase root surface through fine root hair stimulation. Preparing the plants for their first O-MIX Soluble feed, by maximising the root surface area for maximum nutrient uptake.
Application rates:
Kelpak
Apply 1ml/L every 14-21 days
O-Phyte
Apply 1ml/L every 14-21 days
Soluble feed for poinsettias
Poinsettias need a balanced ratio of nutrition. Once the plant has established a firm foundation, growers should make sure the poinsettia is fed everything it needs. Firstly by using the O-MIX range of soluble fertilisers. The range comprises of standard mixes for standard and soft water, and acidifying adjust mixes for hard water. The O-MIX soluble feed is a highly soluble pre-mixed NPK, which ensures every nutrient you add to your stock tank makes its way to the plant, meaning nutrient use efficiency is maximised and money is well invested.
Plugs and newly transplanted plants will benefit from one or two High P O-MIX 11-42-11 feeds to provide additional rooting and essential plant energy ready for the vegetative phase. Growers should monitor P levels within the plant, as additional feeds of 11-42-11 maybe be beneficial before bracts start to form, when plant energy is key.
Poinsettias prefer a balanced N:K ratio feed, therefore switching onto O-MIX 21-7-21 + Mo will provide an ideal balance of raw nutrition. As standard this mix includes a generous TE package, as with all O-MIX soluble feeds, along with additional Molybdenum. Molybdenum is essential for nitrogen assimilation within plants, and poinsettias are notoriously susceptible to Mo deficiency, along with zinc deficiency,
Once bracts have formed one may wish to switch onto a higher K ration, such as O-MIX 15-5-30 feed if the plants are beginning to become too tall.
Foliar feed for poinsettias
Base nutrition can be complimented with foliar applications of fertiliser. Bio 20, which contains a range of NPK, Kelpak and trace elements including Molybdenum and Zinc. will help meet vital nutrient needs of a successful poinsettia feed programme.
Poinsettias, as you’ll be well aware, are notoriously hungry crops with a relatively high water requirement, with this in mind it’s important to monitor active nutrition levels within the plant by taking regular SAP samples. Constant watering can create the risk of flushing out key nutrients, Ca and Mg deficiencies regularly occur. Regular foliar applications of CalMax Ultra will help prevent tip burn in new growth and help with inervenal chlorosis in the older leaves.
Alongside ensuring nutrient levels remain topped up throughout the growing cycle, foliar applied nutrition can also assist with deficiencies. If your poinsettia crop is suffering with deficiency a foliar application of Micromex, containing a robust trace element package which includes Molybdenum and Zinc, will help alleviate symptoms and restore the plant back to good health.
Foliar nutrition can also assist in boosting the plants natural defences. Zynergy, which uses a highly plant available copper and zinc formulation, helps enhance plant health.
Application rates:
CalMax Ultra
1L/ha every 2-3 weeks
Micromex
1-2ml/L as deficiency occurs or low levels detected by SAP Sampling
Zynergy
0.5ml/L + NA13 at 0.1% every 7-10 days.