Most all soil that has not been chemically fertilized has Mychorrizae. Unfortunately the soil in nursery pots has usually had chemical fertilizer, so it may be deficient in Mychorrizae. I am not an organic gardener, but reseach has shown this problem. Fortunately the best rhododendron and azalea fertilizer, Hollytone, is organic. Actually I seldom use fertilizer. Rhododendrons don't need much. It is much more important when planting to prepare a large hole with a good rich acidic humous soil. Excellent drainage is extremely important, but in your area sandy soil is common so that may not be a concern. Then open up the root structure of the plant. Potted plants end up with their roots wrapped around the inside of the pot. If planted this way they will very likely die in a few years when they become root bound. Spread the roots out in the hole and cover up with good moist acidic soil. Never plant deeper than it was originally. It is best to plant a little higher. Be careful to not damage the very fine roots. They are the important ones. Water thoroughly. Now mulch with a couple inches of organic mulch, not stone. If you want a real treat, go to Rarefind Nursery in Jackson, NJ. They are the premier rhododendron nursery on the East Coast and have many other nice plants. They know what they sell. Hank Schannen is the proprietor and has an excellent staff. You will need directions. They have a website at: Rarefind Nursery in Jackson, NJ Here is a link that might be useful: How to Grow Rhododendrons and Azaleas

You are somewhere in the San Joaquin Valley, and get regular frost in winter, don't you? The Cistanthe grandiflora and Calandrinia spectabilis are two different names for the same plant, and this one is somewhat frost tender and you'll want to protect it or plant in a favorable spot if you want it to remain perennial. Gaultheria mucronata prefers cooler coastal climates rather than hot inland valley heat, so best to grow it with only morning sun and try to keep it cooler. I am not familiar with that particular species of Alstroemeria, but most of the Chilean species are winter growers that go dormant in summer and prefer to stay on the dry side when dormant. It appears that the A. umbellata is a higher elevation alpine grower that would be under snow in winter; so in habitat would be a spring into summer grower. I'm not sure whether it will be as easy to grow as lower elevation forms from Chile. Annie's Annuals which does mail order and has an excellent web site would list other species Alstroemeria that have proven successful here in California, and of course there are thousands of hybrids and cultivars if you are interested in low growing forms. The Dutch hybrids in the Princess series are superior garden forms that stay below 12 inches tall and bloom nearly all year round for me. As already mentioned, the Puya venusta gets huge eventually, but it will be at least 5 years out from seed before you really noticed. Give it at least 5 feet clear from any walks or structures to be safe, and I like to use thick mulch over heavy duty weed fabric around this plant so I don't have to mess with fighting weeds around those sharp Puya leaves. You should check out the link to the Chilean Flora web site that I've linked to for more thorough information on where these all grow in Chile, photos, and maybe a better idea of what conditions they will prefer here. Most all the Chilean plants I use in garden designs are from coastal or mountain forest habitats, and probably not as suitable in the inland parts of California. I particularly like the perennial Calceolaria species, and grow several of these as well. Annie's Annuals also carries quite a few interesting Calceolaria species if you're interested. Here is a link that might be useful: Alstroemeria umbellata

"hardpack clay. Really hardpack. So its going to be a huge work in progress just working that soil." Start collection organic matter and spread it or turn it into the areas of the yard you will be planting. I've at times used a digging fork to just loosen the soil where compacted (plunge in, pull back or wiggle, pull back out, repeat) rather than digging, and then spread organic matter on top. You can do that to improve the soil while you plan so that when you're ready to plant, the soil is in better shape for your plants. You could also plant a deep-rooted green manure crop such as annual rye grass or buckwheat to help break up the soil and add organics. Just mow it down before it goes to seed. Some free sources of organic matter I've used: Manure from a neighbor's horses, but you could also use chicken manure if neighbors have chickens (as is legal in some cities) as long as it will have time to age, or manure from pet rabbits. Wood shavings from wood turners or other woodworkers. Chips from tree trimmers - I just ask if I see them in my area, and they will dump on the drive and I just have to wheel barrow them around to where I want them or pile onto a tarp and pull. Adding nitrogen will speed up the break down of woody material. Best if it's just spread on the surface, since breakdown can take a while and may tie up nitrogen if it's turned in. But it will keep the soil evenly moist and the smaller it is with more green matter like leaves, the faster it will break down. It's also a great top coat for newspaper or cardboard. Leaves - When we were just starting, we picked up other folks' bagged leaves from the curb. We avoided homes with pristine lawns since they may have used weed-n-feed, which has herbicides that may create garden problems. Some towns have free compost available for residents, but you have to haul it yourself. Buckets or heavy trash bags full in your car, or a borrowed or rented truck may be used for transport. Around me the big box stores rent trucks by the hour. Newspaper and cardboard - I layer this in and it breaks down fairly quickly, but reduces weeds and grass sprouting from empty beds. If there are things already growing I don't want, I cut them short, and then put several layers of newspapers (black and white only) or a layer of cardboard down and then top with something like woodchips for a tidy appearance and to hold them down until I get around to planting. When I spread compost which may have weed seeds, or manure which usually has seeds, I top that with newspaper or cardboard and then woodchips. When I am ready to plant, I move aside the woodchips, plant, and then push the woodchips back to near, but not against stems. Bought, but less expensive sources of organic matter include anything you can pick up or get delivered by the truckload rather than bag by bag. A single pickup load of compost will probably take care of the entire garden several inches deep. Plan the day of delivery and hire a teenager or two to help move it if you don't have the energy to get it moved out of the dump spot on your own. I'd love to hear how this project goes for you.

I tried them 2 years ago with mixed results. I planted indeterminate tomatoes in 7 gallon fabric pots & these raised beds. Same varieties, same age (raised from seeds), and the same amount of sunshine. I lined the sides of the fabric pots with large garbage bags to help hold in the moisture. The plants in the fabric pots were still hard to keep moist and I don't know if that was the reason they didn't do as well or if it was some other factor. They weren't even half the size of the ones in the raised beds and production was also greatly reduced. On the other hand, I planted eggplants & ground cherries in the 3 & 5 gallons pots and they did fantastic!! The plants were very happy and production was great. I also lined the inside with garbage bags to help with moisture control and they were still hard to keep the dirt moist; but those plants didn't seem to care.