Can you buy potting soil that has NO nutrients in it?

per..... https://www.todayshomeowner.com/why-arent-the-flowers-in-my-garden-blooming/

Annuals

Annual plants typically bloom for most of the growing season. If they stop blooming, it may be caused by:

• Overfeeding: Nitrogen promotes leaf and stem growth, so too much nitrogen results in green plants with no blooms. Even a balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium might have too much nitrogen for your flowering plants.
• What to do: Water your plants really well to wash away some of the nitrogen. Stop using your current fertilizer and give your plants a few weeks’ rest before switching to one with little or no nitrogen and extra phosphorus. Fertilizers labeled as “bloom-boosting” usually have better proportions for flowering plants.
• Heat: Some plants stop flowering when stressed by the heat, particularly if overnight temperatures rise too high.
• What to do: There’s not much you can do for heat-stressed plants other than keeping them alive and healthy until the weather changes.

• Cold: While cooler temperatures are often vital for the setting of flower buds, a dip too low can freeze the buds and cause a season without blooms.
• What to do: Choose plants that are hardy in your climate, and protect tender plants from cold temperatures.
• Light: The amount of sunlight is crucial to getting plants to bloom. Sun-loving plants won’t bloom in shade, and shade-loving plants have trouble in too much sun. Also, some plants are “photoperiodic,” which means they bloom in response to the change in the length of daylight as the seasons progress.
• What to do: While you can’t change the seasons, you can make sure your garden is getting the amount of sunlight required by your particular plants. Check to see if trees or other plants have grown tall enough to shade your garden, and move plants to a different location if there’s not enough (or too much) sunlight.

• Water: While all plants need water, some—particularly desert plants and highly drought-tolerant plants—slow or stop blooming when overwatered. On the other hand, water-loving plants can stop blooming during drought.
• What to do: Check each plant’s individual water needs to make sure you’re not over or under watering.
• Underfeeding: Container plants especially are vulnerable to nutrient depletion.

What to do: Amend your soil with compost and organic matter, and feed with a fertilizer lower in nitrogen and higher in phosphorus.

Have you fertilized them?

yes, you can. Most garden stores have just a plain jane top soil with nothing added.

Try using top soil instead of potting soil. You can get a 10 lb bag for a little over $5 at Lowes.

You can!