If you are not pruning at the wrong time of year, your flower buds, which are set late in the season the year before, are likely being killed by freezing temps in late winter or early Spring, you may not have flowers on hydrangea macrophylla without providing some kind of winter protection. Typically, you will experience several days where you feel like winter may be hinting at leaving you, followed by yet another hard or Spring freeze and the buds are lost.

In colder climates, you may be able to prevent the loss by protecting over winter and not removing the protection until danger of hard freeze has passed. An alternative would be to grow it in a large container, and move that container into an unheated garage or porch during the worst of your weather.

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There is a variegated lacecap hydrangea that many nurseries advertise as being hardy to Zone 5 but many people post complaints about not getting flowers. Can you tell if the one in the link resembles yours. If so, check two things: make sure that you are not pruning it at the wrong time and apply some winter protection.

This hydrangea, simply called Variegata, develops invisible flower buds starting sometime after July-August. The buds then open in Spring. So if you prune in October, you would cut off the blooms. This variegated hydrangea is best pruned after it has bloomed (so you can enjoy the blooms) but before the end of June.

If you notice that the stems dry out & die during winter and if you also notice that all new growth originates from the base/crown then the shrub is not hardy and needs winter protection.

There is another variegated hydrangea that is advertised as hardy to your zone and is called 'Mariesii Variegata'. The leaves on this one do not have as much variegation on the edges of the leaves. Both are lacecaps.
http://www.monrovia.com/plant-catalog/plants/1460/variegated-lacecap-h ydrangea.php

A few other things to check... if you have stems from last year that survive, notice if the flower buds open, make sure that there are no deer or squirrels nearby and make sure the plant does not loose soil moisture (flower buds are the first things to be aborted, then the leaves turn brown from the edges inwards). If there are stems that survive but do not produce blooms, winter could be the culprit but also make sure that you are not applying too much fertilizer (once a year in Spring is fine) and make sure that the plant is not in dense shade.

This post was edited by luis_pr on Fri, Apr 12, 13 at 17:13

Let's clarify the names a bit :-) H. macrophylla 'Mariesii Variegata' is misnamed - should be 'Maculata' (although still widely sold under the old name). It is NOT a sport of 'Mariesii'. The hydrangea commonly sold as 'Variegata' is a serrata, not a macrophylla....although one would be hardpressed to tell the two apart :-)

The variegation of the two is nearly identical, as are the flowers. The difference is that the serrata ('Variegata') is hardier than the macrophylla ('Maculata'), although both will experience bud damage to the flowers in zone 5 without winter protection.

IME, neither variegated form blooms as heavily as any of their nonvariegated cousins......and that's kind of a testament to variegated plants in general. There tends to be some vigor lost with that lack of chlorophyl :-)