Sorry to double-post but I was doing more researching and I was wondering how I would hybridize seeds in order to create broccoflower and how long would that take?

Do you have broccoli and cauliflower flowering now in your area?

'Early Dividend' broccoli takes 43 days from transplanting to maturity. It would require longer to flower and longer still to produce mature seeds.

The earliest cauliflower take 50 days from transplanting and may need a cold treatment, called vernalization' before it will flower.

Both these have small flowers and removing the stamens from them before the buds open might be quite time-consuming, delicate and difficult.

You may not have enough time to do all that is required.

Perhaps you could purchase broccoli, cauliflower and broccoflower seed, grow them and describe how the broccoflower would be produced without actually trying to do so.