The health of the plants in most vegetable gardens is influenced by many factors – but one of the most important of these is the kind of watering they get.
This becomes especially important if you are growing in containers and spaces that are enclosed, since in these conditions water is affected by some factors which are different from beds in an open garden. In our experience many of the growing problems terrace and balcony gardeners face – perhaps over 50% of the disease – is attributable to over-watering of their plants.
We’ve noticed that even gardeners who have experience growing ornamental plants (and maalis too) struggle with understanding the different approaches required for growing vegetables. Most ornamental plants that you will grow are pretty hardy plants by selection and hence seem to be more immune to excess watering. As a result you can blast away with a hosepipe (which makes us cringe) with few adverse results.
Growing vegetable plants is very different and we’ve seen that more plants are killed or lose productivity due to problems created by over-watering than by under-watering. Close observation is important for people new to vegetable growing because often the plants indication of distress are very similar (wilting of leaves) in both over-watering and under-watering situations.
Some visible symptoms of an over-watering problem
- If several plants seem to be wilting and dying or suffering from fungal disease. The leaves will be yellowing or browning or have dis-coloured spots before they shrivel and die. Some plants are more susceptible to these problems than others (tomatoes, brinjals, cucumbers etc). However wilt related problems can be an indicator of systemic over-watering.
- If you see that your soil has a coating of moss (even a slight a greenish tinge). This is an indicator of excess moisture being retained for long periods and needs to be addressed immediately.
- If you see either a high degree of soil compaction or depressions in the level of soil your pots. The first (compaction) is frequently caused by overwatering and the second (depressions) are usually a sign of significant erosion caused by watering at high pressure or a leak in the pot where soil is flowing out with the water.
Systemic solutions that help reduce problems due to over-watering:
- Get your soil/medium right: If you are watering yourself (or have a sensible gardener), then coco-soil can be beneficial because of its high water retention. But if you have concerns about over-watering then a more sand medium is a safer bet.
- Water less – think moist but not soaked/wet: Drenching the soil creates an environment with less aerated soils and for many soil borne diseases to thrive. Just because the surface of the soil is dry doesn’t mean it isn’t wet just below the surface. Poke your finger a couple of inches in and if there is excess moisture, skip watering till the next day.
- Regularly check for proper drainage of excess water out of your pots: The drainage holes in your pots can get blocked from time to time and result in stagnation. Check them by watering deeply and ensuring that the water drains out quickly without stagnating for long periods.
- Water in evenings so you lose less moisture to evaporation: While excess wetness is a problem, plants grow much better if some moisture is always present in the soil. Your plants will be able to take up the moisture better overnight, and additional watering in the mornings will be needed only in really hot conditions. Some plants are adversely affected by watering in hot sunny conditions.
- Water the soil and not the leaves: Many plants are more likely to have disease if their leaves are soaked (especially the tomato/gourd varieties), so the majority of the water should go to the soil. Also, by watering closer to the soil there is less soil damage due to the force of the water.
- Watch that water pressure! Your water pressure needs to be as low as possible to ensure that the water dribbles (not blasts) out of the hose. Its difficult for the less patient gardeners and perhaps less satisfying, but shooting your plants with water is a terrible habit you need to lose immediately. Ideal watering can be achieved by using a 250ml plastic bottle pierced with a few holes (like Twist soda) to replace the shower head on your watering can – it delivers a soft and gentle spray.
- Seedlings should NEVER be watered with a hose-pipe: Most of us are unable to regulate the flow to be gentle enough to make sure that the watering is not too hard and the volume of watering is not high. Best to stick with the watering can with shower for your nursery to improve seedling health.
As one of our guides in kitchen gardening (Miguel Braganza) keeps reminding us – just because a little of something is good (water), doesn’t mean that a lot of it is better.