What signs? There's a bunch of different ones. Some are by the zodiac, or the suns position, or the moon phase.. There's also things like waiting till lilacs bloom to plant beans, or plant corn when oak leaves are the size of squirrel ears.

Some of it can be OK- like planting under Taurus which is mid-May to mid-June is wise, since that's a time frame a lot of northern gardeners put in bean seed. But it does not have an impact on the vine or bean production- that's growing conditions through the season. Often if the weather is good enough for the lilacs to be blooming, it's also warm and good enough to put bean seed in. Often being aware of the seasonal growing around you can help you know when to do your gardening.

Some of this wisdom or old wives tales came from a needed place long ago. People needed to pay attention to the stars and local growing to indicate to them when it was time to sow, grow, reap. Now a days we apply science to it. Though many people still have dates, like planting out for Mothers day or Memorial day. Reaping before Halloween- not because of old notions, but more often now because by then the cold wets and frosts are coming in, and the fields should be clear and stored.

Some people do pay mind to the eight points of the year, and what that means to their gardens. Mostly pagan minded, but it does tick off the seasons fairly well for some.

Thank you very informative remark !!