The gardening season is well underway. And while it's probably too late to plan a garden from scratch, there's still plenty of things you can do to up your game and increase your yield. Best of all, most of these tricks won't cost you a dime.

Mulch like crazy
Of all the ways to increase your yields, decrease the number of hours you spend in the garden, and protect the health of your soil, mulching may be the most important. If you haven't already mulched the crap out of your plants, do so now as the heat of summer kicks into full gear. Mulch will retain moisture in the soil, it will keep weeds down, it will add organic matter and it'll keep the soil critters happy too. From cardboard to newspaper or shredded leaves, there are plenty of free mulch materials available. Pine straw has become my mulch of choice, and I often go deep — applying as much as a foot of pine straw around my tomatoes. (No, it doesn't make your soil acidic.)

Use urine for fertilizer
Feed the soil, not the plants. That's the mantra of most successful organic gardeners. Nevertheless, however much compost and other organic materials you add to the soil, there are times when your plants are going to need a little boost. Many gardeners claim that the best solution is the one closest to home: diluted human urine can be a great source of potassium, nitrogen and phosphorus for plants. In fact, one study suggests that urine-fertilized tomato plants significantly outperformed those given mineral fertilizers.

Hack your watering
As the weather gets hotter, inadequate or inconsistent watering can put significant stress on plants — especially container plants. Try this trick from gardener Douglas Welch as a great way to provide a gradual trickle of water to a plant's root zone throughout a hot, sunny day:

Leave nothing behind
When the harvest season kicks into full gear, it's easy to get overwhelmed and leave food unpicked. Instead of letting tomatoes rot on the vine, try getting creative about how you use them: canning, freezing, pickling and drying are all great ways to preserve food you can't use right now. Look for new recipes and different ways to use fruit. (My wife recently made a delicious chilled cucumber soup to use up our surplus). And we also get generous with neighbors and friends — delivering cucumbers and tomatoes to anyone who will take them. Even fruit that's fallen from the plant is often salvageable: I scavenge fallen green tomatoes and either cook them, or let them ripen on the windowsill.

Don't forget to top dress
OK, so you dug in a whole bunch of compost when you planted your plants, but how long ago was that now? While incorporating compost into the soil does provide a steady, slow release of nutrients, it can also be worthwhile to add compost as a top dressing — especially as fruiting season kicks in. Beware, however, that it's possible to get too much of a good thing. Try adding a handful of compost every three to four weeks and watch carefully to see how the plants react.

Try compost tea
Compost tea, a preparation made by soaking compost in water and aerating it to increase microbial activity, can also be a great way to give soil a boost, and may even help control plant diseases when added as a foliar spray. As with so many things, the Internet is full of lively discussions about the best way to make effective compost tea. Some say you can throw compost in a bucket, stir it a few times, and spray after 48 hours. Others say use an air stone to aerate it. Yet others say you need an aquarium pump or even a pricey, dedicated compost tea brewer to make sure you get enough oxygen to feed the mini-beasts. Check out my post over at TreeHugger on how to make compost tea for more information.

6 tricks for growing more food for less money
The gardening season may be halfway done, but it's not too late to try these thrifty tricks to increase your harvest.