Tips

Tip: A new product available at hardware stores are "planter wall blocks" - concrete bricks with notches to insert boards. These blocks can be stacked to make tall beds. Newer pressure treated lumber does not contain arsenic and is safer than older pressure treated boards. Cedar or redwood boards will last longer than soft pine but cost much more. Even untreated cheap pine boards should last several years before needing replacement.

Tip:  Some newer build housing (post ~2000) has extremely low quality "fill" that consists largely of rocks and chunks of construction debris. If you can barely get a trowel into the ground without hitting rocks and debris, strongly consider using raised beds or containers rather than trying to work with the existing "soil".

Tip: One way to improve the quality of your soil is to add a few inches of good quality composted material on top of the existing soil. Bags of additives such as cow manure, LeafGro, municipal compost, or better quality "topsoil" mixes can be used.  LeafGro is a great local product in the DC area produced in Montgomery County that currently costs around $6 for 1.5 cubic feet, but is also available by the truckload from bulk suppliers. Avoid if possible the super cheap bagged "topsoil" sold at many big box stores as the quality is very low and your plants will likely struggle.

Tip: If using manure from a local farm, use caution with manure that has a high straw content. Some sources of straw treat their straw with broadleaf herbicides that can damage vegetable plants.

In the DC area, the safe outdoor planting date for after last frost is generally considered to be Mother's Day weekend. If you want to start the seeds indoors and then plant the seedling outdoors, the packet will indicate how many weeks in advance the seeds need to be started. 

Tip: To avoid fungus gnats, add in a small amount of Mosquito Bits (available at hardware stores or online) to your soil mix. These release a type of bacteria that kills mosquito and gnat larvae, and are safe for humans and pets.

Tip: Expensive "grow lights" are not necessary. A simple led or fluorescent shop light with a timer will work just fine, but you want to get the light just a few inches above the seedlings, and have a way to adjust the height of the lamps as the seedlings grow. If your light gives off a lot of heat, it might fry or singe the seedlings if it gets too close. If your seedlings are leggy - tall and thin - they do not have enough light. Either add more lights or move the light closer to the seedlings.