Science Forums 2

[maikeru]

Originally Posted by davidgmills

On the day before Valentine's day, I bought my wife some herbs and put them in a single pot with my homemade terra preta.

The news is bad for my cilantro. The rosemary is doing great.

What did I do wrong to my cilantro? Soil is well drained. TP stayed surprisingly moist. I am wondering if cilantro can not stand the excess water retention of TP. Any ideas?

I know this sounds obvious, but different plants have different nutrient requirements. Your cilantro may be suffering from some kind of nutrient deficiency or induced nutrient deficiency because of the charcoal in the soil. And, IIRC, cilantro, when given the chance, will grow faster than rosemary. My rosemary seems to grow rather slowly but steadily. (Edit: I just remembered one more thing after I posted this. Rosemary thrives in poor but well-drained soil. So it may not be as picky as the cilantro when it comes to growing conditions.) The charcoal needs to be saturated with nutrients and after a while I think the soil ecosystem gets going and works with the plants to help improve growth.

I'm growing cilantro in terra preta and it does very well, but I've intentionally added a lot of different things to my terra preta, so I think there are a good collection of nutrients in it. As a quick fix, try adding some dried, low-sodium seaweed. Seaweed is a good source of trace elements and minerals as well as calcium, iron, and potassium. It also has growth hormones in it which may boost plant growth and health in the short-term. I also believe that terra preta has to be "tailored" to a certain extent for the plants intended to grow in it. Leafy plants require more N in the soil. Flowering and fruiting plants may require more K than N. In general, just try to enrich the soil with everything you can get your hands on.


Worse than having plants that don't grow is watching them be taken over by whiteflies. My mother purchased some herbs from the supermarket which have whiteflies, and they're in the same room as my garden, and my plants are infested... Disaster seems to strike when I least expect it. And worse that I didn't notice 'til too late what with being busy recently. The experiment will be over soon, although it has been wonderful and more productive than I ever expected. For example, I've never seen green onions which were 0.5 inches thick or more and 1.5 - 2 feet tall. They even tolerated the winter cold surprisingly well.

I will restart a new indoor herb garden in a few weeks, with the coming of spring, and I will take my current terra preta and use it in the outdoor garden. However, the new terra preta garden will probably use powdered activated charcoal, so I can make more pots more quickly and with less backbreaking effort. I found a site which sells horticultural powdered charcoal. And I will write about my results and take a few pictures to show on the forum.