Ashly Haagsman & Candice Lapointe Greenhouse Blog

October 12-14, 2012

Over our weekend practical we completed many essential tasks for the Fanshawe poinsettia crop (Euphorbia pulcherrima). The most important task we completed was watering and fertilizing the crop. “the hand that holds the hose controls the crop.”. It was a meticulous job. Poinsettias are in the Euphorbia Family and therefore are required to dry out in-between watering. Over watering can lead to root rot in the Poinsettia. We needed to observe the crop for any plants requiring culture and apply the correct amount of fertilizer, to ensure the crop did not get fertilizer burn.

Some symptoms we were looking for were wilting, browning, crinkling of leaves, a light feeling to a pot compared to a watered one, the media pulling away from the side of the pot or light brown media (as its watered it turns dark brown).

Euphorbia pulcherrima wilting. It could be caused from lack of watering or overwatering causing root rot

 

Euphorbia pulcherrima showing symptoms of requiring water. Notice the media pulling away from the sides of the pot. To ensure the media is water toughly it needs to be applied slowly

We used the Dosatron to apply a 250ppm fertilizer to dark coloured Euphorbia pulcherrima cultivars (Red Glitter, Christmas Feeling, Winter Rose, Christmas Day, and Classic Red). And 300ppm for the light coloured cultivars (Polar Bear, and Poly Pink).

They were watered one bench at a time to ensure the Dosatron and drip lines were working correctly. We tagged the drip lines that did not work to ensure they got watered accordingly and that the lines were fixed promptly.

We took a drip line out of a poinsettia and placed it in a measuring cup to ensure 300ml of water and fertilizer were applied to the poinsettias.

We noticed while watering that the water was not very blue, implying that there was no fertilizer coming from the drip lines. The Dosatron seemed to be in working order and the hose that was used to flush the lines was blue. However, when we checked the other hose in the greenhouse (on the far end) after the Dosatron was “working”, its line also had to be flushed in order to run blue. As per last week’s greenhouse class, the Euphorbia pulcherrima were on par with what is expected as per Ecke “OnTrack” website.

The Euphorbia pulcherrima required no further watering over the weekend, although they were monitored

Browning of the leaves could show signs of requiring water or fertilizer burn.