Buy seaweed-based plant feed which can be used as a foliar spray and for watering.
Why Use Liquid Feed Compared to Solid?
Foliar spray is a very effective way of giving plants nutrients as plants can directly absorb the feed through the pores on their leaves. This is much faster than feed which is absorbed through the soil by the roots of the plants.
How to Use Liquid Fertilisers?
Liquid feed can be applied to plants both by foliar spray and by watering the plants with the feed solution. Please ensure that you dilute the feed in water and don't spray it directly. Typically dilution requires 1-5 ml of feed per litre of water.