My first garden was a very minor success, almost a failure if you look at it wrong. I did get a few veggies out of it, and some of the thickest, prettiest grass you ever saw! But I learned so much from that one little patch of dirt. Looking back I wouldn't change a thing. My understanding of gardening was that you till up the dirt, plant seedling and hover like a mother hen, watering and weeding, pruning and with any luck harvesting. I had some luck with the corn and squash, and actually grew some lettuce. This is when I learned about mulching to control weeds. It was too late for some of it, but now i knew. In my digging around I learned about Lasagna Gardening.
You can look it up if you want to. Some of it, and even what I read back then will give you specific proportions of this and that. You can also look up Sheet Mulching if your in a permaculture mood. I used what I had. The basic idea is to lay down something like cardboard or news paper (several layers if you use paper) On top of that you layer leaves, compost, manure, yard clippings, kitchen scraps...you get it. If you do this in the fall, by spring you have a rich, weed freeish area to work with. Yes, I said freeish. Since you don't turn the "compost" you will have some things try to sprout on their own. But because the soil underneath will have been worked by worms, and the roots and grass will have time to decay, weeding will be easy.
AND SO, back to the point.
Perennial plants tend to be more expensive than annuals so I only add a couple a year. By doing this I can take the best care of them so they will take care of me from then on.
I already have one row of Asperagus, about 15' long (about 7 crowns when planted). This year is it's 3rd year so I can harvest it fully for about 3 weeks. Then you let it go to seed to allow the roots to gain the nutrition for next year. I plan on planting another row behind it.
Another of my favorite garden perennials is Horseradish. It does need to be dug and replanted from cuttings, but it is such a hardy plant and we love the spice. I have one good patch going and intend to spread it out.
When you dig up the root to use, cut about 2" off the bottom and 1" off the top and replant (trim off leaves).
This year I plan to add Egyption Walking Onions. These are a shallot size onion. The nodules that they produce at the top of the stalk just get buried as you harvest the onion in the fall and are the start for the next season.
When the stalks turn brown, harvest, or cover with mulch and let them set up for a larger harvest next season.
Last year I grew a few strawberries in a container. I just ate them as I cut herbs to dry for later. I bought what I canned and cooked with from a local farmer. I think they would be a good project for this year.
Finally Jerusalem Artichoke.
Aside from just being pretty, these have an edible root and are prolific growers. The root is good for people and as a great supplement for livestock. Around here (SE Illinois) they grow along ditch banks on the back roads and I hope to get my roots for free. Oh yeah, and fruit trees. But I have a whole plan for those that I will share with you next time.