- Joined
- Nov 7, 2012
- Messages
- 5,173
- Location (City and/or State)
- South of Southern California, but not Mexico
If I got a hibiscus at let's say home depot, how long would out take before it grows out the pesticides and is safe for my tort?
This is the rule of thumb I use.
I buy the discounted plants at Lowe's (Home Depot does not do this anymore) and wait for them to grow out all new leaves. Older leaves I pluck to encourage faster turnover. In all about a year. Re-potting or putting them in the ground helps too for the chance there is some residual in the soil.
Many systemic chemicals are applied as a spray and are up-taken directly through the living parts of the plants. It is systemic plant chemicals that are the worry, not fertilizer obtained through the roots. Most systemic compounds have a life in the plants tissue where they are ever less and or degraded. others are applied to the soil and go into the plant through the roots. In this later case is why a soil change helps. Most systemic chemicals would be destroyed by soil microbes pretty quickly if in the ground, but in a pot with relatively sterile soil, that does not happen as fast.
As an example of a systemic fertilizer you can think of the Miracle Grow watering devices with the fertilizer already in a small bottle that you attach to the hose end. What hits the leaves acts systemically, and with another good watering or rain the residue will mostly wash off and that is okay to feed. That is called a foliar application. The exact same fertilizer can be mixed and poured on the soil, and there is no residue on the leaves and what get taken up by the roots has to a great extent been filtered by the roots.
However if some insecticide or weed killer has been applied in a greenhouse setting that is the worry, so waiting a year with plucked leaves and new soil has been my rule of thumb.