I purchased, on a whim, a packet of my favorite wildflower seeds (California poppy, cornflowers, etc.), but I don’t have a yard that I can plant them in since I rent. I do have a handful of large-ish pots that I can keep outside (used to grow tomato vines). The packet instructions indicate sprinkling the seeds over open ground/garden area. But can I put some in a pot and successfully grow flowers (assuming correct sun and water conditions)?
Planting seeds in large pots is tricky. Takes some skill to not over water.
The most important thing you can do if planting in pots is use potting soil. I know, I know...Alephzero said not to. Garden soil in pots is the kiss of death for any plant or seed planted in a pot with garden soil.
Don't ever buy potting soil with gimmicks such as water holding gels or sponges. Make sure there is NO added fertilizer in that potting medium.
Potting medium has very little soil if any. The major point is this medium is STERILIZED. In the larger body of garden soil out of doors there are balances, checks for disease and insects. Not at all in a pot in doors.
FIRM the soil before planting a few seeds. Cover the seed with 1/8th inch NO MORE of potting medium. Moisten with a spray bottle to 1/4" no more. When your plants germinate, begin watering a little deeper. The problem with a large pot of soil and tiny plants is that there aren't any roots to suck up the excess water. Root rot and damping off of seedlings will happen...especially if you use garden soil that comes with hundreds of spores of fungus...always.
Make sure that you do not use any rock, gravel or packing peanuts between the hole in the bottom of your pot and below that potting soil. Use just potting soil in your pot.
Do not fertilize until there are 3 sets of leaves on your plants. Depending on the size of your pot you will have to pull excess plants so that a few make it to maturity.
Use Osmocote 14-14-14 all purpose extended release fertilizer. Or, make sure that the fertilizer is balanced; that there is N P AND K in that formulation. Hopefully a few micro chemicals (nutrients) even bacteria and mycorrhizae, beneficial fungal spores. Use HALF what the directions prescribe.
Once your plants you've decided to remain are 6" high, then start watering more deeply. Allow that soil to dry before watering again. Never soak the soil and water every day...until your plants are a few feet high...
btw, what size are your pots? Starting seeds in containers or cubbies in trays that are 2" deep by 1" wide is perfect. One seed per cubby. Easy to transplant into a 3" X3" pot (always only potting soil)! Then transplant into 6" pots.
When the out of doors temperatures are stable and above 50 degrees even at night, you can think about planting them in your planting beds. You have to acclimate any plant grown indoors to be able to handle the out of doors and direct sunlight. That means taking the babies out during the day for 15 minutes no more. Same for the next 3 days. Then increase the time to 30 minutes...for three days. Increase that to 1 hour for 3 days...then 2 and 3 and 4 hours. Takes time but to take a plant grown inside on a window sill or even from under artificial lighting and put it out of doors in the sun will FRY your plant. Kill it.
Taking a plant from out of doors to live indoors requires the same amount of acclimation and effort.
If you plant seeds in your pots, in potting soil and water only as deep as there are roots you should be fine. Get ready to THIN your plants, earlier the better so that the roots don't get entangled and make thinning more dangerous for the plants you choose to live.
Make no mistake. It is a hard a fast rule that any potted plants have to have sterilized potting soil, never ever use garden soil! Trust me.
my plants grown in 50/50 mix..garden potting soil mix. fertilize with organic 8-4-4 ...once a week.sadly for my wildflower pot no poppies but some nice beautiful blooms...the tickseed flower is gorgeous.. oddly the blood red center that bleeds outward, is only red on the top portion of the pedals. The underside remains yellow...🤔🤔🤔🤓and