Stopping plants

If you are growing an annual border from seed then I would suggest stopping is not an issue - let the plants develop naturally. If however you are growing annuals you have raised or purchased as individual plants then stopping them at about 2.5" by pinching out the growing tip no more than .5" will not only speed up establishment but ensure bushy plant are developed. this practice is certainly good for French and African marigolds, Antirrhinums, Ageratum, Petunias, Zinnias, seedling pelargoniums, Salvias, Coltness Dahlias, Stocks, Calendulas and Tagetes. Plants I would not stop include Eschscholzia, Nemesia, Violas (Summer pansies) Sunflowers, Larkspur, Nigella, Ricinus (Castor Oil plaant), Poppy, semperfloren begonias - all the foregoing 'non stoppers' will either form basal shoots or are plants which are single stemmed. Hope this note is of use. In the absence of knowing which annuals you are growing it is very difficult to be more precise. Hopefully some, if not all, of the names I have given are on your list. Best wishes dioon11

Not a stupid question at all! Think of your annuals as an hourglass - plant on top, roots on bottom, "stem" in the middle. Removing growing tips up top allows energy to flow into the roots. Creates larger root base, which in turn feeds the top to grow larger "to match". As Dioon11 said, what you grow from seed is likely to have a good root base. What you buy has a cramped and sometimes trimmed root base. Those need to be balanced out by stopping. When in doubt, do one side of the plant and see what happens!