My vegetable garden smells like ripening cantaloup. The air is hot, the humidity is high, it's been a sizzling summer. The vegetables have grown well, so well so that I never remember to carry a container large enough to harvest ripe fruit. Between tomatoes, peppers, watermelon, cucumbers and corn, it's been fantastic!

The tomato 'Kellogg's Breakfast' was one of the first to produce beautiful, large ripe fruit, a golden orange in color. This particular tomato takes 80 days from seed to maturity and it's been well over 100, so its perfectly logical to expect fruit. If indeed it would have taken 80 days for me to pick my first 'Kellogg's Breakfast' tomato, I would have plucked it off the vine on June 21st, a great plan but a silly notion.

Many things determine when a plant flowers and there are various conditions that drive a plant to that stage of maturity, be it with fruit or flowers. The nursery industry has spent immeasurable amounts of money to determine why a plant flowers and how to make it flower earlier or set fruit more profusely. Despite the fact that much has been done to perfect the flowering cycle of chrysanthemums and poinsettias, much more needs to be done to understand the vagaries that drive higher oil content in herbs or flowering cycles in new annuals. These studies have become highly evolved and so utterly fascinating!

You see a plant must first pass through a number of milestones to reach sexual (flowering) maturity. Between petunias that can mature in a matter of days to a European Beech that takes thirty to forty years, it is understood that the longer lived a species is, the longer the juvenile phase lasts. The maturity of a plant can totally determine whether it will flower or not and even override any other method of pushing its sexual maturity.

The degree of light, the intensity of light can also affect maturity. It's believed that adulthood can be reached faster with better light, a reason why some plants reach their maturation before others. Sounds logical but often overlooked. More true with woody plants, perhaps, but certainly true with perennials and annuals as well.

Furthermore cuttings can be taken from adult stock and resulting rooted cuttings are adults. A perfect example of this is Hedera helix or English ivy. It takes 5 to 10 years for the adult stage, the flowering and fruiting stage. At that point the plant does not produce advantageous roots along the stem and flowers form which are fertile and produce seed. Very often the leaves have evolved into something shaped quite different from the juvenile ones. When propagated from this adult via cuttings, the ivy plant grows like a small tree, not a vine, flowering and fruiting.

This is why many of the flowering annuals are vegetatively propagated or grown from cuttings, they are more likely to flower better. There is also something called day length or photoperiodic response. If you have ever wondered why your moonvine won't flower before September, it's about day length. Many other vines are affected by this, examples include hyacinth bean (Dolochis lablab) and firecracker vine (Mina lobata). Both of these are annuals, easily grown from seed, but it's not about their maturity, rather the length of each night.

These vines require short days to flower and wait for the long days of summer to shorten. Many of the salvias respond to this as well as coleus and plumed celosia. The bulk of common annuals are actually day neutral, flowering during both short and long day lengths. Examples include impatiens, vinca and begonias.

Heat and cold are yet another driving factor, the industry readily splits them up into hot or cool crops. My tomato preferred the warmest days of spring and early summer. The ideal daytime temperatures for tomatoes are in the eighties with night temperatures between sixty and seventy degrees. Yes, it can be too hot to set fruit, the flowers won't accept pollen. In fall it quickly becomes too cold for the plants to produce new flowers, especially when nights drop below fifty degrees.

And if it had been eighty degrees every day after I set my tomato out, I would have picked that first fruit in June. On the opposite side, spinach and mustard are cool season plants, they are also short day flowering. A sowing of either from seed right now would be a complete failure in our climate, they would leap from seed to flower.

Zinnias are an example of an annual that likes it hot and they have been bred to be day neutral, a real boon since the days of short day zinnias or those that would only flower in late summer. We like to think that newer is better, that the vast amount of research truly means a longer season of bloom or a larger harvest of vegetables. But sometimes it's hard to fool mother nature.