The Reason for you getting Mold may be that the plant has gotten too Acidic and taken on too much water !
And this is generally because of too much Nitrogen in ratio to the needed Alkaline Minerals !
You may need to learn to feed it a very Dilute solution of Epsom Salt water with some BSM and very small amount of Kelp and , heck, just give it some of the Alkalizing Drink made with Lemon juice !
I had a Lady feed one of her flowers which was about dead, some of the drink and she had to show it to me, as it came Alive from the Dead !
I have grown Solid stem Clovers and Oats and Ryegrass and Alfalfa etc !
You just have to learn to regulate the Nitrogen to the Alkaline Minerals and Acids and have enough moisture and sunlite !
Too much Nitrogen Causes the Plant to take in too much water and then the plant becomes too Acidic and then Mold sets in !
As far as what vegetable I like to grow, it would be Broccoli !!!!!!!!!!!!!
I Love My Broccoli, for it taste Excellent and is packed full of health ingredients !
In second place would be my cabbage for it is sweet tasting and supplies much Calcium and other Alkaline Minerals !
Smile Tis your choice.