Plant Feeding and Composts - Frequently Asked Questions
- This Compost looks different to previous years.
- The pieris and skimmia I grow don’t thrive. A year or so after planting the leaves start to turn pale between the veins. What can I do?
- Can you explain the differences between the John Innes Composts?
- Why do roses and other plants need pruning?
- Why can’t I use my own garden soil to pot up plants?
- I hear some gardeners recommending the use of Fish, Blood and Bone Meal when planting out shrubs and trees. Is it any good?
- Why are there so many different plant foods?
- Can I re-use the compost in my patio pots for more than one year?
Q. This Compost looks different to previous years.
A. All compost producers are following Government guide-lines to reduce the peat content of their composts. At Scotts, we are justly proud of our environmental record and our wide range of composts contain varying levels of peat from Levington Seed & Cutting Compost which contains 100% peat to Miracle-Gro Organic Choice All Purpose Peat Free Compost and Miracle-Gro Compact Compost which are totally peat-free. The rest of our products have varying levels of peat and peat substitutes so that we are able to reduce the total amount of peat used by gardeners.
Q. The pieris and skimmia I grow don’t thrive. A year or so after planting the leaves start to turn pale between the veins. What can I do?
A. This is a symptom of chlorosis which is caused because the roots can’t take up the necessary iron from alkaline soil. These plants need an acid soil or the addition of sequestered iron regularly. Treat the soil area just as you would for rhododendrons, azaleas and camellias. At the beginning of the year sprinkle Murphy Sequestrene Granules around the root area and then feed during late Spring and Summer with Miracle-Gro Ericaceous Plant Food. Both products will supply iron in a form that plant roots can quickly and easily absorb.
Q. Can you explain the differences between the John Innes Composts?
A. John Innes Composts are soil-based growing media made from a mixture of loam, sand or grit and peat with increasing amounts of plant foods added. Levington John Innes Seed Compost contains the smallest amount of nutrients as this encourages the best germination and growth of tiny roots and shoots. Levington John Innes No.1 Compost has a little more nutrients and is for transplanting seedings; Levington John Innes No.2 Compost for when you are potting small plants and Levington John Innes No.3 Compost has the most, as this is designed for final planting up of plants ready for display or cropping.
Q. Why do roses and other plants need pruning?
A. If left to grow untrimmed, roses and other plants grow taller than normal and only produce blooms at the very top of these branches. Don’t be frightened of pruning plants back - you are only making sure they bloom down at a realistic level so you can more easily enjoy their beauty and scent. Use a sharp pair of secateurs and trim back stems by about two thirds.
Q. Why can’t I use my own garden soil to pot up plants?
A. Try it and you will soon see the reasons. For one thing soil doesn’t hold as much water as a good organic based potting compost so you will have to water more often or your plants will suffer. Soil won’t naturally contain as much nutrients so plant growth will be slower and the main elements may not be in the right proportion. What soil lacks in nutrients it may make up for in weed seeds, soil$ pests and harmful bacteria, so watch out. When compared with the cost of the plant you are growing, the cost of sterile, top-quality compost is minimal.
Q. I hear some gardeners recommending the use of Fish, Blood and Bone Meal when planting out shrubs and trees. Is it any good?
A. In theory this is a balanced plant food offering a good supply of all three nutrients. In practice the nutrients are released over different time scales so the plants don’t receive balanced feeding at any one time. For example, the nitrogen in blood and fish meal is released almost immediately giving a rush of greening effect that will last only a few weeks. On the other hand the phosphates in steamed sterilised bone meal will have little immediate effect on growth. The phosphates start to be released after a few months, gradually releasing this one nutrient over several years.
Q. Why are there so many different plant foods?
A. Because we grow so many different plants in different ways. We grow plants in garden beds and border soil and in composts in patio containers and hanging baskets. And people want to feed their plants in the most convenient way for them - either once or twice a year or perhaps weekly when they are watered. There are general plant foods that are beneficial to all plants. These include Miracle-Gro Water Soluble Plant Food and Miracle-Gro Controlled Release Plant Food. They are applied differently but give the same end result - bigger, better plants that have many more beautiful flowers. There are also specialist plant foods for plants that prefer acid soils at the roots - these are most often called ericaceous plant foods.
Q. Can I re-use the compost in my patio pots for more than one year?
A. It’s not advisable, as the compost may be harbouring vine weevil larvae and other insect pests. Tip out all containers each year and spread the spent compost thinly over the soil surface to give birds a chance to eat up any insect pests. Pot up your plants in fresh compost each year to provide correct feeding for many weeks and to minimise any carry over of pests and diseases.
