Expert Instructions on the corect care and handling of plug plants during the first couple of weeks during and after pricking out.
This time in the plug plants life is critical to the plants final performance and one error here, can make the difference between strong healthy final plants, and sickly specimens susceptable to fungal infections, poor root growth and plant stress.
These instructions will cover six fundamental topics, which if mastered together will lead to better success with your growing plants. They are; Watering, Plant Handling, Temperature, Light Levels, Growing Medium (Compost) and lastly Feeding.
Wet at the bottom Do not hold by the stem A crab pick, ideal for -
Dry at the top Only by the leaves and roots extracting plugs from trays
Plant roots do their job best when the soil is moist, but not waterlogged, and preferably warm, so first important lesson is to let the water warm up to room temperature before using it to water young plants (water straight from the tap is probably about 4 to 5 degrees centigrade! That's a very cold shower for baby plants.) A perfectly watered plant pot will be damp at the bottom, but the top half centimeter of the pot will be fairly dry - see photo. The best way to achieve this is to water the plants from undeneath, either by standing them on damp capilliary matting or dipping them in a water tray for a few minutes - with plug plants not yet planted, dipping the plug into water is without doubt the best method.
Watering overhead should be avoided, but if you do have to water by this method ensure that the water droplets are as small as possible (fine mist or light rain) as heavy droplets can actualy bruise delicate leaves, also try to put in good air circulation as damp moist leaves are more prone to fungal infection than dry ones, finally keep out of direct sunlight, as water droplets on the leaf can act as a magnifying glass and burn the leaves.
If the unthinkable happens and the plants wilt DO NOT WATER IN FULL SUN, as this will kill the young plants, instead soak the roots in a water tray and cover the plants with a sheet of damp newspaper or put them under the bench in the dark until they have recovered. This is actually a very important lesson with any plant, no matter how big, if the plant is wilting and you water the leaves in full sun, the leaves are guaranteed to burn (go brown and dead round the edges varying with the extent of wilting).
For the first watering straight after pricking out, you must completely saturate the entire pot, either by immersion or by 2 or 3 waterings in quick succesion.
Plug Plant Handling
The most vital part of the young plant is the stem, and this can be easily bruised by even the lightest touch. Once damaged in this way, the internal channels that transfer water and nutrients from the roots to the leaves will stop working in the bruised area and permenant damage results. The other area not to touch is the central growing point, as this are is very tender and damage here can disfigure the final shape of the plant.
Now the parts you can touch, these are the leaves and the rootball. To pick the plant up, pick the leaves between your index finger and thumb and support the rootball with your little finger - see photo above - try not to pinch the leaves harder than you have to.
If you are pricking the plugs out of a plug tray and cannot get them out, try these tips; soak it in water, wet plugs come out more easily than dry ones; push the plugs up from underneath through the bottom hole of the tray with the end of a dibber or similar; hook the rootball out of the plug tray with a crab-pick or similar - see photo.
Always make a hole in the compost before inserting the plug and make sure the surface of the plug is not buried, you should also gently firm the soil back around the plug so as to avoid any large air gaps.
Temperature for growing
The Optimum temperature for most plants is between 10 and 15 degrees centigrade and if you can give them slightly more warmth from below (under bench heating etc) this will encourage quicker root growth. Lower temperatures will slow down growth, but keep the plants more compact, whilst higher temperatures will make the plants grow faster, but this can cause them to become leggy and weak. Do not let them get close to freezing as this can cause damage to the leaves, whilst 25 degrees and above will stop the plants growing and cause them stress.
Best light levels are from diffuse overhead sunlight, beware of direct sunlight as this can cause burnt leaves (see watering) or if too intense can overheat the leaves. Too little light, and the plants will tend to grow long and leggy. If you suffer from light coming from one direction only (through a window, against a high wall away from the light etc.), then make sure you turn the plants round on a regular basis (once a day - not longer), otherwise the plants will grow lopsided towards the light.
Growing Medium (Compost)
Use a free draining compost for potting on, preferably one with slow release fertilizer, wetting agent and a proportion of Soil based (JI) compost.
Feeding and Sprays
As young plants have very tender leaves and stems compared to their older brethren, the use of any feeds or sprays is strongly discouraged as it can lead to burnt or disformed leaves. Once a plant is established and rooted through in its growing container, then you can start feeding or spraying with pesticides if required. We however would always reccomend the use of biological pest control wherever possible.