Need to know how to build a greenhouse? You’ve come to the right place, once you have determined your budget, available land, and greenhouse location. From annuals and perennials to flowering shrubs and small trees, it's easy to fall in love with new plants to add to your garden. But if you live in a cold climate—or if you want to start seedlings for a vegetable or flower garden early to get a jumpstart on spring—you need a greenhouse. You'll be able to save some of your favorite plants for the next season, as well as shelter tender plants or seedlings until you can set them out in the spring. Even if you don't have tons of space, there are greenhouses that will fit tidily up against your house or on your patio or deck. Another option is a cold frame, which generally is lower to the ground but also warms up the soil and allows you to plant sooner in the spring. Just remember that many budget-priced options are not meant to be permanent so they won't stand up to wind or heavy snow.Now, check out a few DIY and inexpensive greenhouses you can buy to make your plants happy.