I have no experience growing in your zone and have never grown corn, so I can't give you any advice there either, altho I understand corn is a heavy feeder(?). However, just because the soil "looks" good, doesn't mean it IS good. After many years of this elderly couple gardening, they may have exhausted the soil. Fertilizing will help, but imo, nothing beats amending the soil with compost, manure, etc. In my area we're having a bizarre season with much, much cooler than normal temps and tons of rain so that's playing havoc with my garden - don't know the conditions of your area, but it could just be a fluke as well. Don't get discouraged tho!! You're young and have years of wonderful gardening experiences ahead of you! We all have years where some things just don't work and you can't always explain it. It is frustrating, however, but again, try to not get discouraged. Best of luck to you in your new home and garden!! :) Lisa

Try adding soil amendments with organic manures such as chicken/cow/horse manure and digging it into the soil before you plant and then mulching the bare soil. Adding organic amendments will help greatly with regulating soil moisture, which is the greatest problem with starting new plants from seed. A simple trap for earwigs is to leave rolled up newspaper in the garden, and the earwigs will gravitate to hide in them, you can then toss into the trash or shake them out and stomp them. The Bananas, Brugmansia and Calla Lilies are all likely to do better in a sheltered spot with mostly shade, unless you are in an area with direct coastal fog influence, and all will want to stay moist in the warmer/drier months. Brugmansia in particular will look better if you give it some time release fertilizer such as Osmocote or feed with fish emulsion regularly. The Zantedeschia aethiopica is more of a winter grower in southern California/northern Baja California, and is inclined to go dormant once the temperatures get warmer. If it gets winter rains and is planted in a spot with shade or only morning sun, it will likely burst into full growth again next rainy season. If you want Calla Lilies, the summer blooming hybrids with yellow/orange or pink flowers are probably better for Tijuana conditions, just keep them well watered and fed. Nasturtiums are probably also going to do better for you as a fall planted seedling growing through the winter, and declining as it gets warm, unless grown with sufficient shade and water. I'd suggest sticking with flowers that really prefer heat and can take a bit of drought, and African and French Marigolds should thrive for you, as should most Verbena species and hybrids such as V. rigida, V. bonariensis, and V. hybrida. If you have room for some rampant vines, I'd bet that common Morning Glory would do well, as would Bougainvillea, Thunbergia alata or T. gregorii. Succulents such as Cotyledon orbiculata, Sedum dendroideum, Euphorbia xantii and E. tirucallii 'Sticks on Fire', Echeveria agavoides and E. imbricata, Agaves such as A. parryi, A. bracteosa, A. attenuata, Aloes, etc. Now that it has finally warmed up, it is safer to be overwatering new plants, and they won't rot/drown from too cold/wet soil conditions. It may have been mostly a problem of too cool conditions for new warm season seedlings, in combination with soil with insufficient organic content to hold onto to soil nutrients and water. Aged chicken manure or rabbit manure and/or liquid fertilizers such as fish emulsion on a periodic basis should turn your luck around immensely. Don't give up, enjoy your garden, and good luck on the employment aspect!

I think I might have misinterpreted your question. When you said "hydrangea tree, I thought you were referring to the PeeGee variety, which is often trained as a tree. (You can buy it from nurseries already started as a tree form.) You can read up on PeeGee and see a few photos here. If you were referring to potting any type hydrangea, be it PeeGee 'tree' form or any 'bush' form, then the answer to your initial question in general is "yes". PeeGee is tough and will withstand our winters and bloom just fine. But other varieties, it's touch and go depending on our weather. So that's why I pot my more unusual or delicate varieties, so they have protection in the garage. I find Target has nice decorative plastic pots that aren't terribly expensive. I have Nikko in the ground as well as All Summer Beauty, Domotoi and Endless Summer. It's hit or miss whether I get a good bloom show, our winter can be hard on them. This winter was Endless Summer & Domotoi's first winter in my flowerbed. ES is loaded with blooms, but Domotoi isn't showing any yet. It's a later bloomer, but still, I think it might have to be potted, just too darn cold here for it. I just went out & took some pics for you. Here's 3 of my potted ones. On the deck is a "Pia" (a dwarf variety, hardy in our zone but I wanted it potted for the deck). In the gray pot on the right is "Masja" (a beauty and full of buds this year!) and in the largest pot in the back is "Ayesha". That's the one with the drastic curly-q outer limbs. Some of my "in the ground" hyds also get curly-q on the outer stems, but not as drastic. Ayesha is already in a whopping big pot, but still would do better in a bit larger one. I forget how many gallons the Ayesha's pot is, but it's the largest size you can find at most retailers. Here's my PeeGee tree form, by the pond. Looks a little sparse right now, it's just beginning to leaf out. As you can see, it takes up minimal ground space, it's the upper branches that need space. One of the mistakes they made with it (and why it was probably reduced to $5) is they didn't prune to get the "V" high enough off the ground. I'm trying to train it to a better shape, which takes a long time. So if you decide to buy a PeeGee tree form, look for one that has has a longer trunk for balance when it matures (I'd suggest 4' from ground level, minimum). I use good potting soil (I like Fertilome's "Ultimate" potting mix, it's supposed to be a good mix for container planting). I use water crystals in the soil at planting time. Then I add a good 2" layer of mulch to the tops of the pots. I find I have to drench them regularly in the heat. I feed them with Schultz Bloom Plus for Acid Loving plants because I prefer bluer blooms. I also keep them under a tree where they get dappled sunlight. I bring them into the garage around late October (I don't let a hard frost get them). In winter I water maybe once every 10-14 days, no fertilizer since they're sleeping. And I bring them out of the garage in late April/early May. I wait till the trees have leafed out so the canopy it creates is added protection should we have a late spring frost.

One of the hardest lessons I had to learn, for outdoor (veggies) versus indoor (in-pot) growing, was to forget "dont over-water your plants." While it was good advice for stuff in pots, to keep them from drowning in their little cubicles, garden vegetables grown in a raised bed environment need a constant supply of adequate moisture to thrive. There are some similarities between "pot growing" and container raised beds or in-soil growing, but letting the soil dry out between waterings is a problem I had to resolve. Vegetables need a constant supply of moisture to produce well. Also I had to fertilize more in the vegetable garden with additional phosphorus and potassium to make better flowers and fruiting. Of course, learning about "special" needs of the vegetables helped a lot. Some preferred more potassium, phosphorus or nitrogen than others. Learning/tending/protecting them with daily visits helped a lot. Many wild critters and bugs prefer "eating plants" to flowering/ornamental plants. Of importance, staying tuned to these informative posts every day to find out about other folks with their successes/failures, with similar interests can be of real value. Bejay