Leaves turning Yellow

[TerraceGardener]

Hello, I am new to gardening. I started growing some vegetable plants in my terrace garden in a raised bed but all my plants growth stunted and leaves are turning yellow and dying. The growing medium consists of Vermi Compost, Cocopeat, Red Soil and Neem Cake in 1:1:0.6:0.2 ratio and I am watering the plants twice daily. Attached photos are of young tomato and Eggplant plants. Please advice. Thank you!

[rainbowgardener]

Looks malnourished.

I don't know what "Red Soil" is and I am only familiar with Neem as a spray oil , against pests and fungus. I don't have any idea how it would function in soil.

That's a pretty high ratio of peat and peat is difficult to work with in soil. It adds no nutrients. It sucks up and holds water and then dries out and repels water.

Most potting mixes, especially for very young plants like yours have a third or so of mineral ingredients like perlite. That helps promote drainage, keep the soil loosened up and fluffy.

Have you been fertilizing?

[applestar]

Good points, though I believe neem cake and vermicasting can provide some fertilizing component. I also think they look a little dehydrated -- or overwatered and roots are having difficulty with uptake -- despite (or DUE TO) the twice daily watering. How much water do you give them each time, and so you check and make sure that the amount of water has soaked in? For 2nd watering, do you check to make sure they need it before watering?

Vermicompost and cocopeat/coir should be water retentive when sufficiently soaked. Red soil -- is that a type of clay?

If they got dried out and lost some of the roots at some point, the plants might look like that as well.

[TerraceGardener]

Neem Cake is obtained by powdering neem seeds, it acts as a fertilizer and pesticide. As I have also added vermicompost, I have not applied any other fertilizer yet.

This is the description and characteristics of red soil that I found specific to my area:
1) Formed by Weathering of crystalline and metamorphic rocks.
2) Mixture of clay and sand.
3) Red in color because of high Iron-oxide (FeO) content.
4) Deficient in Nitrogen, Lime, Phosphoric acid and humus.
5) Rich in Potash.

I give about 150ml of water in the morning and slightly less water in the evening. By evening the top layer gets dried out but it retains lot of moisture at 2 inches deep. Should I let it completely dry out before watering again? I stopped watering them since yesterday to see how they would turn out.

[imafan26]

This is a terrace garden. 150 ml is not a lot of water, it is about 5 oz which is very little. I am not familiar with how your soil mix would balance out but pretty much I don't use any compost except a handful of vermicompost in my potting mixes. Most aerobic composts are alkaline and that can lock up the micronutrients. Stunting usually means they are not getting enough room or enough food. Your container looks big enough so, I think it is not getting the nutrients. Some of your leaves have a reddish cast to them that could be either from Sulfur or nitrogen deficiency. If your mix is alkaline and poor in Sulfur it would make nitrogen less available. I would use ammonium sulfate but you could try elemental sulfur and fish emulsion. I know you are growing on a terrace but it is better to water planter well and evenly let it drain completely with no saucers or actually grow your plants in SIPS so the water can be contained in a reservoir. Water again when the soil is just barely damp 2 inches down. In a SIP you would only have to watch the level in the reservoir and make sure it does not empty. You can mulch the top of the soil to slow down evaporation from the top.

I have used coco peat before, it is hard to manage water with it. It is very wet when it is watered and when it dries it is very dry. It is very hard to keep it evenly moist and it packs down over time. All I did was add equal parts coco peat and perlite for drainage. I did add a little vermicompost and used sustaine which is a dry fish meal fertilizer. It is touted as a replacement for sphagnum moss because it is more renewable, but it just does not perform as well over time.