In container culture, which is more like hydroponics than gardening, it's always better to use a fertilizer or supplement your fertilizer with something that provides all the secondary macro and all the micronutrients. Almost any soluble fertilizers you'd choose to use provide NPK in various %s. Many also provide Fe, Mn, and Zinc (Miracle-Gro formulations e.g.). Usually glaringly absent are the secondary macronutrients Ca and Mg. Including a micronutrient supplement and liming your soil insures a full compliment of all the nutrients. In short - choose a fertilizer that HAS ALL the nutrients or use a micronutrient supplement, and lime homemade soils with dolomitic (garden) lime. Hard to find, but very effective at supplying the micronutrients are Micromax and STEM. Easier to find is Earthjuice Microblast. One fertilizer in the 3:1:2 ratio that contains ALL the elements (including Ca and Mg) is Foliage-Pro 9-3-6. This fertilizer alone should be excellent for most things you would grow. Use it at a reduced rate & combine it with Pro-TeKt 0-0-3 for a lower N mix for tomatoes. The silicon on the Pro-TeKt will also improve cellular health & make for a stronger plant that resists cultural adversities (heat, cold, insects, disease . . . better. Though irrigation water DOES have an impact on nutrition (usually mostly Ca/Mg), unless you know it's content via analysis, you shouldn't rely on it to insure adequate levels of any of the nutrients. Al

One difference between regular concrete and hypertufa is its life. It depends a lot on your local conditions, but hypertufa is generally considered to only have a lifespan of about 10 years, if that. The main source of problems is the inclusion of organic materials like peat, which will rot away, leaving "worm holes" where water can migrate through the hypertufa and freeze, cracking and weakening the project. Your friend can probably give you some good advice on how to create what you have in mind, that will have a longer life, and I think he will probably recommend regular concrete. And keep in mind that regular concrete will also grow moss. In the beginning, the concrete will be alkaline, which will NOT grow moss. But if it is exposed to rain for a couple of weeks, or you hose it down quite a bit, or maybe even treat it with a baking soda solution, it will become more neutral. Then you can "paint" it with a mix of yogurt and crumbled moss, or buttermilk and crumbled moss, then just keep it moist. It will grow moss better if it is in the shade, too, but there are many mosses -- try growing ones that live around your area. Sue

1. Diatomaceous earth is not poisonous, it works like broken glass, the effect is physical rather than biochemical. It is supposed to puncture the skin of small pests (or the intestines, if they eat it). 2. No, there are many types of cat litter, few are suitable as soil amendment. Avoid everything that is clumping, made from organic materials, or crumbles if you squeeze it. The useful ones are very similar to products like Turface and Napa Floor Dry. All I have seen have been pinkish.

First, the heat comes FROM the garage floor (geo-thermal), so you don't want to isolate the bottom of your containers from the floor, as that would insulate them from the heat source. Set your containers directly ON the floor to take advantage of both conductive and radiant heat coming through and rising from the floor. If your tree is small enough, simply overturn a box and cover the entire tree. The open end of the box goes down - against the floor, and the top of the box is the closed end in this arrangement. If the tree is too large or too tall to completely cover, use the box in the same fashion, but cut a slit in the box and a hole in the top (former bottom) of the box to accommodate the trunk. This usually requires you to measure the appropriate ht of the box and cut it down to that ht so it will accommodate the trunk - especially when there are multiple trunks involved. In the case of multiple trunks, you want the box to be of a ht such that the hole to accommodate the trunks is as small as possible. If Martin's goal is to keep the roots warm, it would be better, when using that arrangement, if he set the boxes up on a shelf. It appears that the bottom of the box (unless it is open) is isolating the plants from the heat source (the floor). Cold air sinks to the floor, so the coldest spot in the garage is immediately above the floor. If the pots are insulated from the heat source, root temperatures will be colder on the floor than at any other spot in the garage. An open top doesn't trap heat from the floor, either. The method I described not only traps heat from the floor, but it also insulates roots against extreme cold - like if you forget and leave the door open on an extremely cold day. You can try this and monitor temps - you'll be surprised at how warm it is in the box. Also, keep in mind that the slab will be much warmer near the wall common to house/garage if you need to take advantage of that fact. Also - insulation doesn't help unless it aids you in trapping heat IN the box from some other extraneous source. In this case, it would be the floor. Insulation in the overturned box is unnecessary, though I wouldn't hesitate to use a little tape and insulation to seal the slit in the box (if req'd) and to seal the hole around the trunk. Al