Fertilizers and Soil Preparation
Soil preparation for plants in the garden or pots is very important for every gardener or florist. When growing berries in the pots, soil preparation is important even more since amount of soil per plant is much more limited when compared to growing plants in the garden.
When new plant is potted in a new pot, it is best to use new, fresh soil – one has opportunity to buy soil customized for the potted plant. If there is no such soil, a general soil for flowers will do fine – most of the time.
When using old soil for new plants or just want to renew soil in the pot with growing plant, one has to add fertilizers and organic matter.
Mineral fertilizers come in granules or pellets. They are very strong and care must be taken not to overfeed the plants or even destroy the roots.
Beside their NPK content, they usually have some minerals added to them like Fe, Mg, B, etc. Some of mineral fertilizers have envelope or membrane around chemicals, so that they are not dissolved at once, but during longer period of time – some times for months. These fertilizers are also more expensive. Mineral fertilizers are added to the soil, but can be applied to the leafs (special variants) – used rarely for potted plants.
Organic fertilizers come in pellets or briquettes. They are not odorless, so care must be taken to bury the pellets at least 5-6 cm below the surface. Also, just as ordinary NPK fertilizer, organic fertilizers can make burns on the root of the plants, too. Having said that, why should one use these fertilizers at all? Well, they are very rich in organic matter and different minerals. Organic matter decomposes over time and feeds plant with constant supply of nutrients – there are no large nutrients spikes that can happen with mineral fertilizer.
Compost and humus are organic matter that comes from decomposed leafs and similar stuff with little help from microorganisms and earthworms. Their NPK content is relatively low but they are very rich in organic matter and minerals. One cannot overfeed plant with compost and humus. Be very careful - some manufacturers add mineral NPK fertilizers to their compost and humus mixes, so one should carefully read labels – such 'enriched' mixtures can overfeed the plants. Anyway, compost and humus are probably the best choice among the fertilizers, but also most expensive.
Best Fertilizer For Berries?
Which fertilizer is the best? There is no such thing as the best fertilizer – it depends on the quality of soil, on the planted berries, flowers, herbs or simply plants, growing conditions etc.
Even fertilizers for the same plants, for example strawberries and other berries, vary from manufacturer to manufacturer. Generally it is important to know what each plant needs and observe condition of the plants – if they grow slow or they are weak, they need probably everything or pH factor is off. If they are growing too fast with big leaves, there is probably surplus of nitrogen. It is possible to buy little test kits for checking soil quality at home or in the small garden. They don't cost much and they give rather good results. But to get exact result, one should take soil samples to some lab or similarly equipped garden store. Is this necessary? Home kits are in my opinion enough - even they are not needed when soil is properly prepared.
Often, for plants in the pots, it is best practice to once a year simply change potting soil and add some mineral fertilizer with timed release and some humus and compost.
General recommendation: in winter or early spring, add mix of soil and organic fertilizer to the soil. From spring until the end of vegetation period, add mineral fertilizers (always bury it in soil) as they are recommended. Since content of fertilizers vary, I personally never use same fertilizer two times in the row. This is not necessary, but ... Add some compost and humus on top of soil from time to time and dig them into the soil little bit.