Well whether or not you continue use Miracle Grow is up to you of course but many don't care for it, myself included. There are a number of other fertilizers that are much better.

But yes, the plants will need some sort of supplemental feedings approx. every 6 weeks or so if they are in-ground plants and weekly if they are in containers.

There is a really good recent discussion on this called "Fertilizing during fruiting?" linked below along with several other discussions on feeding regimens if you want to read through them.

Dave

Here is a link that might be useful: Fertilizing discussions

I may have just killed my Borage seedlings with Miracle Grow Mir-Acid. They were so healthy looking this morning and I decided to give them a shot of Mir-acid dissolved in water. I come out this afternoon to look at them and the plants look dead and ths leaves are all withered and soft and droopy. I may have saved them by taking the whole pot and plant and putting them underwater completely and then letting them drain. Some of the leaves are starting to get some turgidity back. Borage must be unusually susceptible to fertilizer burn because I watered some tomato, pepper, and cucumber plants with the same stuff and they looked O.K., but just to be on the safe side I watered them heavily with plain rainwater to try to leach the miracle grow out of the pots and off the leaves.

If my plants grow well in the native soil, I don't bother with any fertilizer at all. Like mine right now are growing fast and are super green and lush, so why would I want to feed them, the natural soil will have enough nutrients to last the season like it always does.

However if you want to use MG be careful around fruit set because their all-purpose plant food is high in nitrogen (24%) so that might give you more foliage and fewer fruits.